diff --git a/crypto_kem/ntrulpr653/avx2/Makefile b/crypto_kem/ntrulpr653/avx2/Makefile
index 5d22a4ce..80410df7 100644
--- a/crypto_kem/ntrulpr653/avx2/Makefile
+++ b/crypto_kem/ntrulpr653/avx2/Makefile
@@ -4,7 +4,7 @@ LIB=libntrulpr653_avx2.a
 HEADERS=api.h crypto_core_multsntrup653.h crypto_core_multsntrup653_ntt.h crypto_decode_256x16.h crypto_decode_256x2.h crypto_decode_653x1541.h crypto_decode_653x3.h crypto_decode_653xint16.h crypto_decode_653xint32.h crypto_encode_256x16.h crypto_encode_256x2.h crypto_encode_653x1541.h crypto_encode_653x1541round.h crypto_encode_653x3.h crypto_encode_653xint16.h crypto_sort_int32.h crypto_sort_uint32.h crypto_stream_aes256ctr.h crypto_verify_1025.h params.h 
 OBJECTS=crypto_core_multsntrup653.o crypto_core_multsntrup653_ntt.o crypto_decode_256x16.o crypto_decode_256x2.o crypto_decode_653x1541.o crypto_decode_653x3.o crypto_decode_653xint16.o crypto_decode_653xint32.o crypto_encode_256x16.o crypto_encode_256x2.o crypto_encode_653x1541.o crypto_encode_653x1541round.o crypto_encode_653x3.o crypto_encode_653xint16.o crypto_sort_int32.o crypto_sort_uint32.o crypto_stream_aes256ctr.o crypto_verify_1025.o kem.o 
 
-CFLAGS=-O3 -mavx2 -mbmi2 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -std=c99 -I../../../common $(EXTRAFLAGS)
+CFLAGS=-O3 -mavx2 -mbmi2 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -Wconversion -std=c99 -I../../../common $(EXTRAFLAGS)
 
 all: $(LIB)
 
diff --git a/crypto_kem/ntrulpr653/avx2/crypto_core_multsntrup653.c b/crypto_kem/ntrulpr653/avx2/crypto_core_multsntrup653.c
index 7381e5ca..8c754b1f 100644
--- a/crypto_kem/ntrulpr653/avx2/crypto_core_multsntrup653.c
+++ b/crypto_kem/ntrulpr653/avx2/crypto_core_multsntrup653.c
@@ -291,9 +291,9 @@ int PQCLEAN_NTRULPR653_AVX2_crypto_core_multsntrup653(unsigned char *outbytes, c
         store_x16(&f[i], x);
     }
     for (i = 0; i < p; ++i) {
-        int8 gi = kbytes[i];
+        int8 gi = (int8) kbytes[i];
         int8 gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (int16) (gi0 - (gi & (gi0 << 1)));
     }
 
     mult768(fg, f, g);
diff --git a/crypto_kem/ntrulpr653/avx2/crypto_decode_256x2.c b/crypto_kem/ntrulpr653/avx2/crypto_decode_256x2.c
index 506266a5..db4b2b68 100644
--- a/crypto_kem/ntrulpr653/avx2/crypto_decode_256x2.c
+++ b/crypto_kem/ntrulpr653/avx2/crypto_decode_256x2.c
@@ -3,7 +3,7 @@
 #include <stdint.h>
 
 #define COPY _mm256_set_epi64x(0x0303030303030303,0x0202020202020202,0x0101010101010101,0x0000000000000000)
-#define MASK _mm256_set1_epi64x(0x8040201008040201)
+#define MASK _mm256_set1_epi64x((int64_t) 0x8040201008040201)
 #define MASK2 _mm256_set1_epi64x(0x0101010101010101)
 
 void PQCLEAN_NTRULPR653_AVX2_crypto_decode_256x2(void *v, const unsigned char *s) {
diff --git a/crypto_kem/ntrulpr653/avx2/crypto_decode_653x1541.c b/crypto_kem/ntrulpr653/avx2/crypto_decode_653x1541.c
index 21ae3335..e03c76a5 100644
--- a/crypto_kem/ntrulpr653/avx2/crypto_decode_653x1541.c
+++ b/crypto_kem/ntrulpr653/avx2/crypto_decode_653x1541.c
@@ -10,7 +10,7 @@ static inline int16 mullo(int16 x, int16 y) {
 }
 
 static inline int16 mulhi(int16 x, int16 y) {
-    return (x * (int32)y) >> 16;
+    return (int16) ((x * (int32)y) >> 16);
 }
 
 static inline __m256i add(__m256i x, __m256i y) {
@@ -79,7 +79,7 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
     a0 += s[1 * i + 0]; /* -39...290 */
     a0 = mulhi(a0, 3) - mulhi(mullo(a0, -923), 71); /* -36...35 */
     a0 += (a0 >> 15) & 71; /* 0...70 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, -22153);
 
     /* invalid inputs might need reduction mod 9402 */
@@ -100,7 +100,7 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
         a0 += s[1 * i + 0]; /* -67...325 */
         a0 = mulhi(a0, 10) - mulhi(mullo(a0, -489), 134); /* -68...67 */
         a0 += (a0 >> 15) & 134; /* 0...133 */
-        a1 = (a2 << 7) + ((s[i] - a0) >> 1);
+        a1 = (int16) ((a2 << 7) + ((s[i] - a0) >> 1));
         a1 = mullo(a1, 19563);
 
         /* invalid inputs might need reduction mod 134 */
@@ -119,7 +119,7 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
     a0 = mulhi(a0, 1223) - mulhi(mullo(a0, -5681), 2953); /* -1477...1782 */
     a0 += s[1 * i + 0]; /* -1477...2037 */
     a0 += (a0 >> 15) & 2953; /* 0...2952 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, -9543);
 
     /* invalid inputs might need reduction mod 815 */
@@ -136,7 +136,7 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
         a0 = mulhi(a0, 1223) - mulhi(mullo(a0, -5681), 2953); /* -1505...1514 */
         a0 += s[2 * i + 0]; /* -1505...1769 */
         a0 += (a0 >> 15) & 2953; /* 0...2952 */
-        a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+        a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
         a1 = mullo(a1, -9543);
 
         /* invalid inputs might need reduction mod 2953 */
@@ -158,7 +158,7 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
         a0 = mulhi(a0, 1756) - mulhi(mullo(a0, -1206), 13910); /* -7142...7159 */
         a0 += s[2 * i + 0]; /* -7142...7414 */
         a0 += (a0 >> 15) & 13910; /* 0...13909 */
-        a1 = (a2 << 15) + (s[2 * i + 1] << 7) + ((s[2 * i] - a0) >> 1);
+        a1 = (int16) ((a2 << 15) + (s[2 * i + 1] << 7) + ((s[2 * i] - a0) >> 1));
         a1 = mullo(a1, -13437);
 
         /* invalid inputs might need reduction mod 13910 */
@@ -178,7 +178,7 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
         a0 = mulhi(a0, -101) - mulhi(mullo(a0, -8891), 1887); /* -969...943 */
         a0 += s[1 * i + 0]; /* -969...1198 */
         a0 += (a0 >> 15) & 1887; /* 0...1886 */
-        a1 = (a2 << 8) + s[i] - a0;
+        a1 = (int16) ((a2 << 8) + s[i] - a0);
         a1 = mullo(a1, 5279);
 
         /* invalid inputs might need reduction mod 1887 */
@@ -234,7 +234,7 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
     a0 = mulhi(a0, 2401) - mulhi(mullo(a0, -2487), 6745); /* -3497...3527 */
     a0 += s[2 * i + 0]; /* -3497...3782 */
     a0 += (a0 >> 15) & 6745; /* 0...6744 */
-    a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+    a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
     a1 = mullo(a1, -29207);
 
     /* invalid inputs might need reduction mod 7910 */
@@ -287,7 +287,7 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
     a0 = mulhi(a0, 64) - mulhi(mullo(a0, -12768), 1314); /* -657...673 */
     a0 += s[1 * i + 0]; /* -657...928 */
     a0 += (a0 >> 15) & 1314; /* 0...1313 */
-    a1 = (a2 << 7) + ((s[i] - a0) >> 1);
+    a1 = (int16) ((a2 << 7) + ((s[i] - a0) >> 1));
     a1 = mullo(a1, -399);
 
     /* invalid inputs might need reduction mod 1541 */
@@ -369,7 +369,7 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
 
     /* R1 ------> R0: reconstruct mod 653*[1541] */
 
-    R0[652] = 3 * R1[326] - 2310;
+    R0[652] = (int16) (3 * R1[326] - 2310);
     s -= 326;
     i = 310;
     for (;;) {
diff --git a/crypto_kem/ntrulpr653/avx2/crypto_decode_653xint16.c b/crypto_kem/ntrulpr653/avx2/crypto_decode_653xint16.c
index fc5d7fd2..9af423af 100644
--- a/crypto_kem/ntrulpr653/avx2/crypto_decode_653xint16.c
+++ b/crypto_kem/ntrulpr653/avx2/crypto_decode_653xint16.c
@@ -8,8 +8,7 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_decode_653xint16(void *v, const unsigned cha
     for (i = 0; i < 653; ++i) {
         uint16_t u0 = s[0];
         uint16_t u1 = s[1];
-        u1 <<= 8;
-        *x = u0 | u1;
+        *x = (uint16_t) (u0 | (u1 << 8));
         x += 1;
         s += 2;
     }
diff --git a/crypto_kem/ntrulpr653/avx2/crypto_encode_256x16.c b/crypto_kem/ntrulpr653/avx2/crypto_encode_256x16.c
index b17a2188..4b3a9647 100644
--- a/crypto_kem/ntrulpr653/avx2/crypto_encode_256x16.c
+++ b/crypto_kem/ntrulpr653/avx2/crypto_encode_256x16.c
@@ -5,6 +5,6 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_encode_256x16(unsigned char *s, const void *
     const unsigned char *T = v;
     int i;
     for (i = 0; i < 128; ++i) {
-        s[i] = T[2 * i] + (T[2 * i + 1] << 4);
+        s[i] = (unsigned char) (T[2 * i] + (T[2 * i + 1] << 4));
     }
 }
diff --git a/crypto_kem/ntrulpr653/avx2/crypto_encode_256x2.c b/crypto_kem/ntrulpr653/avx2/crypto_encode_256x2.c
index 058fc8f4..c77f1095 100644
--- a/crypto_kem/ntrulpr653/avx2/crypto_encode_256x2.c
+++ b/crypto_kem/ntrulpr653/avx2/crypto_encode_256x2.c
@@ -29,60 +29,60 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_encode_256x2(unsigned char *s, const void *v
     int32_t c5 = _mm256_movemask_epi8(b5);
     int32_t c6 = _mm256_movemask_epi8(b6);
     int32_t c7 = _mm256_movemask_epi8(b7);
-    *s++ = c0;
+    *s++ = (unsigned char) c0;
     c0 >>= 8;
-    *s++ = c0;
+    *s++ = (unsigned char) c0;
     c0 >>= 8;
-    *s++ = c0;
+    *s++ = (unsigned char) c0;
     c0 >>= 8;
-    *s++ = c0;
-    *s++ = c1;
+    *s++ = (unsigned char) c0;
+    *s++ = (unsigned char) c1;
     c1 >>= 8;
-    *s++ = c1;
+    *s++ = (unsigned char) c1;
     c1 >>= 8;
-    *s++ = c1;
+    *s++ = (unsigned char) c1;
     c1 >>= 8;
-    *s++ = c1;
-    *s++ = c2;
+    *s++ = (unsigned char) c1;
+    *s++ = (unsigned char) c2;
     c2 >>= 8;
-    *s++ = c2;
+    *s++ = (unsigned char) c2;
     c2 >>= 8;
-    *s++ = c2;
+    *s++ = (unsigned char) c2;
     c2 >>= 8;
-    *s++ = c2;
-    *s++ = c3;
+    *s++ = (unsigned char) c2;
+    *s++ = (unsigned char) c3;
     c3 >>= 8;
-    *s++ = c3;
+    *s++ = (unsigned char) c3;
     c3 >>= 8;
-    *s++ = c3;
+    *s++ = (unsigned char) c3;
     c3 >>= 8;
-    *s++ = c3;
-    *s++ = c4;
+    *s++ = (unsigned char) c3;
+    *s++ = (unsigned char) c4;
     c4 >>= 8;
-    *s++ = c4;
+    *s++ = (unsigned char) c4;
     c4 >>= 8;
-    *s++ = c4;
+    *s++ = (unsigned char) c4;
     c4 >>= 8;
-    *s++ = c4;
-    *s++ = c5;
+    *s++ = (unsigned char) c4;
+    *s++ = (unsigned char) c5;
     c5 >>= 8;
-    *s++ = c5;
+    *s++ = (unsigned char) c5;
     c5 >>= 8;
-    *s++ = c5;
+    *s++ = (unsigned char) c5;
     c5 >>= 8;
-    *s++ = c5;
-    *s++ = c6;
+    *s++ = (unsigned char) c5;
+    *s++ = (unsigned char) c6;
     c6 >>= 8;
-    *s++ = c6;
+    *s++ = (unsigned char) c6;
     c6 >>= 8;
-    *s++ = c6;
+    *s++ = (unsigned char) c6;
     c6 >>= 8;
-    *s++ = c6;
-    *s++ = c7;
+    *s++ = (unsigned char) c6;
+    *s++ = (unsigned char) c7;
     c7 >>= 8;
-    *s++ = c7;
+    *s++ = (unsigned char) c7;
     c7 >>= 8;
-    *s++ = c7;
+    *s++ = (unsigned char) c7;
     c7 >>= 8;
-    *s++ = c7;
+    *s++ = (unsigned char) c7;
 }
diff --git a/crypto_kem/ntrulpr653/avx2/crypto_encode_653x1541.c b/crypto_kem/ntrulpr653/avx2/crypto_encode_653x1541.c
index f0a66124..081783f3 100644
--- a/crypto_kem/ntrulpr653/avx2/crypto_encode_653x1541.c
+++ b/crypto_kem/ntrulpr653/avx2/crypto_encode_653x1541.c
@@ -42,26 +42,26 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_encode_653x1541(unsigned char *out, const vo
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
-    R[326] = (((R0[652] + 2310) & 16383) * 10923) >> 15;
+    R[326] = (uint16) ((((R0[652] + 2310) & 16383) * 10923) >> 15);
 
     reading = (uint16 *) R;
     writing = R;
@@ -124,22 +124,22 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_encode_653x1541(unsigned char *out, const vo
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -204,22 +204,22 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_encode_653x1541(unsigned char *out, const vo
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -229,9 +229,9 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_encode_653x1541(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1887;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[10] = R[20];
 
@@ -239,11 +239,11 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_encode_653x1541(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)13910;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[5] = R[10];
 
@@ -251,36 +251,36 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_encode_653x1541(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)2953;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[4];
     r1 = R[5];
     r2 = r0 + r1 * (uint32)2953;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[2] = r2;
+    R[2] = (uint16) r2;
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)134;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)71;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/ntrulpr653/avx2/crypto_encode_653x1541round.c b/crypto_kem/ntrulpr653/avx2/crypto_encode_653x1541round.c
index 878fe438..d994ed24 100644
--- a/crypto_kem/ntrulpr653/avx2/crypto_encode_653x1541round.c
+++ b/crypto_kem/ntrulpr653/avx2/crypto_encode_653x1541round.c
@@ -44,26 +44,26 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_encode_653x1541round(unsigned char *out, con
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
-    R[326] = (((3 * ((10923 * R0[652] + 16384) >> 15) + 2310) & 16383) * 10923) >> 15;
+    R[326] = (uint16) ((((3 * ((10923 * R0[652] + 16384) >> 15) + 2310) & 16383) * 10923) >> 15);
 
     reading = (uint16 *) R;
     writing = R;
@@ -126,22 +126,22 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_encode_653x1541round(unsigned char *out, con
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -206,22 +206,22 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_encode_653x1541round(unsigned char *out, con
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -231,9 +231,9 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_encode_653x1541round(unsigned char *out, con
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1887;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[10] = R[20];
 
@@ -241,11 +241,11 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_encode_653x1541round(unsigned char *out, con
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)13910;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[5] = R[10];
 
@@ -253,36 +253,36 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_encode_653x1541round(unsigned char *out, con
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)2953;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[4];
     r1 = R[5];
     r2 = r0 + r1 * (uint32)2953;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[2] = r2;
+    R[2] = (uint16) r2;
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)134;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)71;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/ntrulpr653/avx2/crypto_encode_653xint16.c b/crypto_kem/ntrulpr653/avx2/crypto_encode_653xint16.c
index 7d60b0c9..f4432f5f 100644
--- a/crypto_kem/ntrulpr653/avx2/crypto_encode_653xint16.c
+++ b/crypto_kem/ntrulpr653/avx2/crypto_encode_653xint16.c
@@ -7,7 +7,7 @@ void PQCLEAN_NTRULPR653_AVX2_crypto_encode_653xint16(unsigned char *s, const voi
 
     for (i = 0; i < 653; ++i) {
         uint16_t u = *x++;
-        *s++ = u;
-        *s++ = u >> 8;
+        *s++ = (unsigned char) u;
+        *s++ = (unsigned char) (u >> 8);
     }
 }
diff --git a/crypto_kem/ntrulpr653/avx2/crypto_sort_int32.c b/crypto_kem/ntrulpr653/avx2/crypto_sort_int32.c
index e1327c65..efa749c2 100644
--- a/crypto_kem/ntrulpr653/avx2/crypto_sort_int32.c
+++ b/crypto_kem/ntrulpr653/avx2/crypto_sort_int32.c
@@ -44,7 +44,7 @@ static void minmax_vector(int32 *x, int32 *y, size_t n) {
         int32x8_MINMAX(x0, y0);
         int32x8_store(x + n - 8, x0);
         int32x8_store(y + n - 8, y0);
-        n &= ~7;
+        n &= ~(size_t) 7;
     }
     do {
         int32x8 x0 = int32x8_load(x);
diff --git a/crypto_kem/ntrulpr653/avx2/crypto_verify_1025.c b/crypto_kem/ntrulpr653/avx2/crypto_verify_1025.c
index 4286184b..33861c45 100644
--- a/crypto_kem/ntrulpr653/avx2/crypto_verify_1025.c
+++ b/crypto_kem/ntrulpr653/avx2/crypto_verify_1025.c
@@ -27,10 +27,10 @@ int PQCLEAN_NTRULPR653_AVX2_crypto_verify_1025(const unsigned char *x, const uns
     diff |= _mm256_srli_epi32(diff, 16);
     diff |= _mm256_srli_epi64(diff, 32);
 
-    differentbits = _mm256_extract_epi8(diff, 0);
-    differentbits |= _mm256_extract_epi8(diff, 8);
-    differentbits |= _mm256_extract_epi8(diff, 16);
-    differentbits |= _mm256_extract_epi8(diff, 24);
+    differentbits = (unsigned int) _mm256_extract_epi8(diff, 0);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 8);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 16);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 24);
 
     return (int) (1 & ((differentbits - 1) >> 8)) - 1;
 }
diff --git a/crypto_kem/ntrulpr653/avx2/kem.c b/crypto_kem/ntrulpr653/avx2/kem.c
index 19ae250f..efa4a044 100644
--- a/crypto_kem/ntrulpr653/avx2/kem.c
+++ b/crypto_kem/ntrulpr653/avx2/kem.c
@@ -18,7 +18,7 @@
 
 /* return -1 if x<0; otherwise return 0 */
 static int int16_negative_mask(int16 x) {
-    uint16 u = x;
+    uint16 u = (uint16) x;
     u >>= 15;
     return -(int) u;
     /* alternative with gcc -fwrapv: */
@@ -38,24 +38,24 @@ typedef int16 Fq;
 /* works for -14000000 < x < 14000000 if q in 4591, 4621, 5167 */
 /* assumes twos complement; use, e.g., gcc -fwrapv */
 static Fq Fq_freeze(int32 x) {
-    x -= q * ((q18 * x) >> 18);
-    x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    x -= (int32) (q * ((q18 * x) >> 18));
+    x -= (int32) (q * ((q27 * x + 67108864) >> 27));
+    return (Fq) x;
 }
 
 /* works for all uint32 x */
 static Fq Fq_bigfreeze(uint32 x) {
-    x -= q * ((x * (uint64)q31) >> 31);
-    x -= q * ((x * (uint64)q31) >> 31);
+    x -= (uint32) (q * ((x * (uint64)q31) >> 31));
+    x -= (uint32) (q * ((x * (uint64)q31) >> 31));
     x -= q;
     x += (-(x >> 31)) & (uint32)q;
-    return x;
+    return (Fq) x;
 }
 
 /* ----- Top and Right */
 
 static int8 Top(Fq C) {
-    return (tau1 * (int32)(C + tau0) + 16384) >> 15;
+    return (int8) ((tau1 * (int32)(C + tau0) + 16384) >> 15);
 }
 
 static Fq Right(int8 T) {
@@ -88,7 +88,7 @@ static void Short_fromlist(small *out, const uint32 *in) {
     }
     PQCLEAN_NTRULPR653_AVX2_crypto_sort_uint32(L, ppadsort);
     for (i = 0; i < p; ++i) {
-        out[i] = (L[i] & 3) - 1;
+        out[i] = (small) ((L[i] & 3) - 1);
     }
 }
 
@@ -99,7 +99,7 @@ static void Short_fromlist(small *out, const uint32 *in) {
 static void Hash(unsigned char *out, const unsigned char *in, int inlen) {
     unsigned char h[64];
     int i;
-    sha512(h, in, inlen);
+    sha512(h, in, (size_t) inlen);
     for (i = 0; i < 32; ++i) {
         out[i] = h[i];
     }
@@ -278,7 +278,7 @@ int PQCLEAN_NTRULPR653_AVX2_crypto_kem_dec(unsigned char *k, const unsigned char
             int8 T[I];
             Top_decode(T, c + Rounded_bytes);
             for (i = 0; i < I; ++i) {
-                r[i] = -int16_negative_mask(Fq_freeze(Right(T[i]) - aB[i] + 4 * w + 1));
+                r[i] = (int8) - int16_negative_mask(Fq_freeze(Right(T[i]) - aB[i] + 4 * w + 1));
             }
         }
     }
@@ -289,12 +289,12 @@ int PQCLEAN_NTRULPR653_AVX2_crypto_kem_dec(unsigned char *k, const unsigned char
         Hide(cnew, x, r, pk, cache);
         mask = crypto_verify_clen(c, cnew);
         for (i = 0; i < Inputs_bytes; ++i) {
-            x[1 + i] ^= mask & (x[1 + i] ^ rho[i]);
+            x[1 + i] ^= (unsigned char) (mask & (x[1 + i] ^ rho[i]));
         }
         for (i = 0; i < Ciphertexts_bytes + Confirm_bytes; ++i) {
             x[1 + Inputs_bytes + i] = c[i];
         }
-        x[0] = 1 + mask;
+        x[0] = (unsigned char) (1 + mask);
         Hash(k, x, sizeof x);
     }
     return 0;
diff --git a/crypto_kem/ntrulpr653/clean/Makefile b/crypto_kem/ntrulpr653/clean/Makefile
index 7807ed9b..c1856934 100644
--- a/crypto_kem/ntrulpr653/clean/Makefile
+++ b/crypto_kem/ntrulpr653/clean/Makefile
@@ -4,7 +4,7 @@ LIB=libntrulpr653_clean.a
 HEADERS=api.h crypto_core_multsntrup653.h crypto_decode_256x16.h crypto_decode_256x2.h crypto_decode_653x1541.h crypto_decode_653x3.h crypto_decode_653xint16.h crypto_decode_653xint32.h crypto_encode_256x16.h crypto_encode_256x2.h crypto_encode_653x1541.h crypto_encode_653x1541round.h crypto_encode_653x3.h crypto_encode_653xint16.h crypto_sort_int32.h crypto_sort_uint32.h crypto_stream_aes256ctr.h crypto_verify_1025.h params.h 
 OBJECTS=crypto_core_multsntrup653.o crypto_decode_256x16.o crypto_decode_256x2.o crypto_decode_653x1541.o crypto_decode_653x3.o crypto_decode_653xint16.o crypto_decode_653xint32.o crypto_encode_256x16.o crypto_encode_256x2.o crypto_encode_653x1541.o crypto_encode_653x1541round.o crypto_encode_653x3.o crypto_encode_653xint16.o crypto_sort_int32.o crypto_sort_uint32.o crypto_stream_aes256ctr.o crypto_verify_1025.o kem.o 
 
-CFLAGS=-O3 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -std=c99 -I../../../common $(EXTRAFLAGS)
+CFLAGS=-O3 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -Wconversion -std=c99 -I../../../common $(EXTRAFLAGS)
 
 all: $(LIB)
 
diff --git a/crypto_kem/ntrulpr653/clean/crypto_core_multsntrup653.c b/crypto_kem/ntrulpr653/clean/crypto_core_multsntrup653.c
index 5b38329b..77d270cf 100644
--- a/crypto_kem/ntrulpr653/clean/crypto_core_multsntrup653.c
+++ b/crypto_kem/ntrulpr653/clean/crypto_core_multsntrup653.c
@@ -14,7 +14,7 @@ typedef int16 Fq;
 static Fq Fq_freeze(int32 x) {
     x -= q * ((q18 * x) >> 18);
     x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    return (Fq) x;
 }
 
 int PQCLEAN_NTRULPR653_CLEAN_crypto_core_multsntrup653(unsigned char *outbytes, const unsigned char *inbytes, const unsigned char *kbytes) {
@@ -30,9 +30,9 @@ int PQCLEAN_NTRULPR653_CLEAN_crypto_core_multsntrup653(unsigned char *outbytes,
     }
 
     for (i = 0; i < p; ++i) {
-        small gi = kbytes[i];
+        small gi = (small) kbytes[i];
         small gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (small) (gi0 - (gi & (gi0 << 1)));
     }
 
     for (i = 0; i < p; ++i) {
diff --git a/crypto_kem/ntrulpr653/clean/crypto_decode_653x1541.c b/crypto_kem/ntrulpr653/clean/crypto_decode_653x1541.c
index 5e07c4bb..edd6d15f 100644
--- a/crypto_kem/ntrulpr653/clean/crypto_decode_653x1541.c
+++ b/crypto_kem/ntrulpr653/clean/crypto_decode_653x1541.c
@@ -30,7 +30,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
 
     *q = 0;
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 2^31 qpart <= xv <= 2^31 qpart + 2^31-1 */
     /* 2^31 qpart m <= xvm <= 2^31 qpart m + (2^31-1)m */
     /* 2^31 qpart m <= 2^31 x <= 2^31 qpart m + (2^31-1)m + x(m-1) */
@@ -42,7 +42,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += qpart;
     /* x <= 49146 */
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 0 <= newx <= (1-1/2^31)m + x(m-1)/2^31 */
     /* 0 <= newx <= m + 49146(2^14-1)/2^31 */
     /* 0 <= newx <= m + 0.4 */
@@ -59,7 +59,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += mask;
     /* x < m */
 
-    *r = x;
+    *r = (uint16) x;
 }
 
 static uint16 uint32_mod_uint14(uint32 x, uint16 m) {
@@ -81,14 +81,14 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_decode_653x1541(void *v, const unsigned cha
     r1 = (r1 << 8) | *--s;
     r1 = (r1 << 8) | *--s;
     r1 = uint32_mod_uint14(r1, 2608); /* needed only for invalid inputs */
-    R10[0] = r1;
+    R10[0] = (uint16) r1;
 
     r2 = R10[0];
     r2 = (r2 << 8) | *--s;
     uint32_divmod_uint14(&r1, &r0, r2, 71);
     R9[0] = r0;
     r1 = uint32_mod_uint14(r1, 9402); /* needed only for invalid inputs */
-    R9[1] = r1;
+    R9[1] = (uint16) r1;
 
     R8[2] = R9[1];
     r2 = R9[0];
@@ -96,14 +96,14 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_decode_653x1541(void *v, const unsigned cha
     uint32_divmod_uint14(&r1, &r0, r2, 134);
     R8[0] = r0;
     r1 = uint32_mod_uint14(r1, 134); /* needed only for invalid inputs */
-    R8[1] = r1;
+    R8[1] = (uint16) r1;
 
     r2 = R8[2];
     r2 = (r2 << 8) | *--s;
     uint32_divmod_uint14(&r1, &r0, r2, 2953);
     R7[4] = r0;
     r1 = uint32_mod_uint14(r1, 815); /* needed only for invalid inputs */
-    R7[5] = r1;
+    R7[5] = (uint16) r1;
     for (i = 1; i >= 0; --i) {
         r2 = R8[i];
         r2 = (r2 << 8) | *--s;
@@ -111,7 +111,7 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_decode_653x1541(void *v, const unsigned cha
         uint32_divmod_uint14(&r1, &r0, r2, 2953);
         R7[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 2953); /* needed only for invalid inputs */
-        R7[2 * i + 1] = r1;
+        R7[2 * i + 1] = (uint16) r1;
     }
 
     R6[10] = R7[5];
@@ -122,7 +122,7 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_decode_653x1541(void *v, const unsigned cha
         uint32_divmod_uint14(&r1, &r0, r2, 13910);
         R6[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 13910); /* needed only for invalid inputs */
-        R6[2 * i + 1] = r1;
+        R6[2 * i + 1] = (uint16) r1;
     }
 
     R5[20] = R6[10];
@@ -132,7 +132,7 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_decode_653x1541(void *v, const unsigned cha
         uint32_divmod_uint14(&r1, &r0, r2, 1887);
         R5[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 1887); /* needed only for invalid inputs */
-        R5[2 * i + 1] = r1;
+        R5[2 * i + 1] = (uint16) r1;
     }
 
     R4[40] = R5[20];
@@ -142,7 +142,7 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_decode_653x1541(void *v, const unsigned cha
         uint32_divmod_uint14(&r1, &r0, r2, 695);
         R4[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 695); /* needed only for invalid inputs */
-        R4[2 * i + 1] = r1;
+        R4[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R4[40];
@@ -151,7 +151,7 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_decode_653x1541(void *v, const unsigned cha
     uint32_divmod_uint14(&r1, &r0, r2, 6745);
     R3[80] = r0;
     r1 = uint32_mod_uint14(r1, 7910); /* needed only for invalid inputs */
-    R3[81] = r1;
+    R3[81] = (uint16) r1;
     for (i = 39; i >= 0; --i) {
         r2 = R4[i];
         r2 = (r2 << 8) | *--s;
@@ -159,7 +159,7 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_decode_653x1541(void *v, const unsigned cha
         uint32_divmod_uint14(&r1, &r0, r2, 6745);
         R3[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 6745); /* needed only for invalid inputs */
-        R3[2 * i + 1] = r1;
+        R3[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R3[81];
@@ -167,14 +167,14 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_decode_653x1541(void *v, const unsigned cha
     uint32_divmod_uint14(&r1, &r0, r2, 1314);
     R2[162] = r0;
     r1 = uint32_mod_uint14(r1, 1541); /* needed only for invalid inputs */
-    R2[163] = r1;
+    R2[163] = (uint16) r1;
     for (i = 80; i >= 0; --i) {
         r2 = R3[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 1314);
         R2[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 1314); /* needed only for invalid inputs */
-        R2[2 * i + 1] = r1;
+        R2[2 * i + 1] = (uint16) r1;
     }
 
     R1[326] = R2[163];
@@ -185,16 +185,16 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_decode_653x1541(void *v, const unsigned cha
         uint32_divmod_uint14(&r1, &r0, r2, 9277);
         R1[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 9277); /* needed only for invalid inputs */
-        R1[2 * i + 1] = r1;
+        R1[2 * i + 1] = (uint16) r1;
     }
 
-    R0[652] = 3 * R1[326] - 2310;
+    R0[652] = (int16) (3 * R1[326] - 2310);
     for (i = 325; i >= 0; --i) {
         r2 = R1[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 1541);
-        R0[2 * i] = 3 * r0 - 2310;
+        R0[2 * i] = (int16) (3 * r0 - 2310);
         r1 = uint32_mod_uint14(r1, 1541); /* needed only for invalid inputs */
-        R0[2 * i + 1] = 3 * r1 - 2310;
+        R0[2 * i + 1] = (int16) (3 * r1 - 2310);
     }
 }
diff --git a/crypto_kem/ntrulpr653/clean/crypto_decode_653xint16.c b/crypto_kem/ntrulpr653/clean/crypto_decode_653xint16.c
index e2299739..22634823 100644
--- a/crypto_kem/ntrulpr653/clean/crypto_decode_653xint16.c
+++ b/crypto_kem/ntrulpr653/clean/crypto_decode_653xint16.c
@@ -8,8 +8,7 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_decode_653xint16(void *v, const unsigned ch
     for (i = 0; i < 653; ++i) {
         uint16_t u0 = s[0];
         uint16_t u1 = s[1];
-        u1 <<= 8;
-        *x = u0 | u1;
+        *x = (uint16_t) (u0 | (u1 << 8));
         x += 1;
         s += 2;
     }
diff --git a/crypto_kem/ntrulpr653/clean/crypto_encode_256x16.c b/crypto_kem/ntrulpr653/clean/crypto_encode_256x16.c
index c985088c..8f425feb 100644
--- a/crypto_kem/ntrulpr653/clean/crypto_encode_256x16.c
+++ b/crypto_kem/ntrulpr653/clean/crypto_encode_256x16.c
@@ -5,6 +5,6 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_encode_256x16(unsigned char *s, const void
     const unsigned char *T = v;
     int i;
     for (i = 0; i < 128; ++i) {
-        s[i] = T[2 * i] + (T[2 * i + 1] << 4);
+        s[i] = (unsigned char) (T[2 * i] + (T[2 * i + 1] << 4));
     }
 }
diff --git a/crypto_kem/ntrulpr653/clean/crypto_encode_256x2.c b/crypto_kem/ntrulpr653/clean/crypto_encode_256x2.c
index 4ab11cd7..d09e48af 100644
--- a/crypto_kem/ntrulpr653/clean/crypto_encode_256x2.c
+++ b/crypto_kem/ntrulpr653/clean/crypto_encode_256x2.c
@@ -8,6 +8,6 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_encode_256x2(unsigned char *s, const void *
         s[i] = 0;
     }
     for (i = 0; i < 256; ++i) {
-        s[i >> 3] |= (r[i] & 1) << (i & 7);
+        s[i >> 3] |= (unsigned char) ((r[i] & 1) << (i & 7));
     }
 }
diff --git a/crypto_kem/ntrulpr653/clean/crypto_encode_653x1541.c b/crypto_kem/ntrulpr653/clean/crypto_encode_653x1541.c
index 1862de4c..77a5cde1 100644
--- a/crypto_kem/ntrulpr653/clean/crypto_encode_653x1541.c
+++ b/crypto_kem/ntrulpr653/clean/crypto_encode_653x1541.c
@@ -15,24 +15,24 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_encode_653x1541(unsigned char *out, const v
     uint32 r2;
 
     for (i = 0; i < 326; ++i) {
-        r0 = (((R0[2 * i] + 2310) & 16383) * 10923) >> 15;
-        r1 = (((R0[2 * i + 1] + 2310) & 16383) * 10923) >> 15;
+        r0 = (uint16) ((((R0[2 * i] + 2310) & 16383) * 10923) >> 15);
+        r1 = (uint16) ((((R0[2 * i + 1] + 2310) & 16383) * 10923) >> 15);
         r2 = r0 + r1 * (uint32)1541;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
-    R[326] = (((R0[652] + 2310) & 16383) * 10923) >> 15;
+    R[326] = (uint16) ((((R0[652] + 2310) & 16383) * 10923) >> 15);
 
     for (i = 0; i < 163; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)9277;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[163] = R[326];
 
@@ -40,29 +40,29 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_encode_653x1541(unsigned char *out, const v
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1314;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 41; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)6745;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 20; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)695;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[20] = R[40];
 
@@ -70,9 +70,9 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_encode_653x1541(unsigned char *out, const v
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1887;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[10] = R[20];
 
@@ -80,11 +80,11 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_encode_653x1541(unsigned char *out, const v
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)13910;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[5] = R[10];
 
@@ -92,36 +92,36 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_encode_653x1541(unsigned char *out, const v
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)2953;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[4];
     r1 = R[5];
     r2 = r0 + r1 * (uint32)2953;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[2] = r2;
+    R[2] = (uint16) r2;
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)134;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)71;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/ntrulpr653/clean/crypto_encode_653x1541round.c b/crypto_kem/ntrulpr653/clean/crypto_encode_653x1541round.c
index a4b969c4..2361d1c2 100644
--- a/crypto_kem/ntrulpr653/clean/crypto_encode_653x1541round.c
+++ b/crypto_kem/ntrulpr653/clean/crypto_encode_653x1541round.c
@@ -11,7 +11,7 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_encode_653x1541round(unsigned char *out, co
     int i;
 
     for (i = 0; i < p; ++i) {
-        x[i] = 3 * ((10923 * a[i] + 16384) >> 15);
+        x[i] = (int16) (3 * ((10923 * a[i] + 16384) >> 15));
     }
     PQCLEAN_NTRULPR653_CLEAN_crypto_encode_653x1541(out, x);
 }
diff --git a/crypto_kem/ntrulpr653/clean/crypto_encode_653x3.c b/crypto_kem/ntrulpr653/clean/crypto_encode_653x3.c
index 34f1f6c4..2dc3dffc 100644
--- a/crypto_kem/ntrulpr653/clean/crypto_encode_653x3.c
+++ b/crypto_kem/ntrulpr653/clean/crypto_encode_653x3.c
@@ -11,9 +11,9 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_encode_653x3(unsigned char *s, const void *
 
     for (i = 0; i < p / 4; ++i) {
         x = *f++ + 1;
-        x += (*f++ + 1) << 2;
-        x += (*f++ + 1) << 4;
-        x += (*f++ + 1) << 6;
+        x += (uint8) ((*f++ + 1) << 2);
+        x += (uint8) ((*f++ + 1) << 4);
+        x += (uint8) ((*f++ + 1) << 6);
         *s++ = x;
     }
     x = *f++ + 1;
diff --git a/crypto_kem/ntrulpr653/clean/crypto_encode_653xint16.c b/crypto_kem/ntrulpr653/clean/crypto_encode_653xint16.c
index 6bb71b20..70193303 100644
--- a/crypto_kem/ntrulpr653/clean/crypto_encode_653xint16.c
+++ b/crypto_kem/ntrulpr653/clean/crypto_encode_653xint16.c
@@ -7,7 +7,7 @@ void PQCLEAN_NTRULPR653_CLEAN_crypto_encode_653xint16(unsigned char *s, const vo
 
     for (i = 0; i < 653; ++i) {
         uint16_t u = *x++;
-        *s++ = u;
-        *s++ = u >> 8;
+        *s++ = (unsigned char) u;
+        *s++ = (unsigned char) (u >> 8);
     }
 }
diff --git a/crypto_kem/ntrulpr653/clean/kem.c b/crypto_kem/ntrulpr653/clean/kem.c
index 6d4eaa4a..a4970a69 100644
--- a/crypto_kem/ntrulpr653/clean/kem.c
+++ b/crypto_kem/ntrulpr653/clean/kem.c
@@ -18,7 +18,7 @@
 
 /* return -1 if x<0; otherwise return 0 */
 static int int16_negative_mask(int16 x) {
-    uint16 u = x;
+    uint16 u = (uint16) x;
     u >>= 15;
     return -(int) u;
     /* alternative with gcc -fwrapv: */
@@ -38,24 +38,24 @@ typedef int16 Fq;
 /* works for -14000000 < x < 14000000 if q in 4591, 4621, 5167 */
 /* assumes twos complement; use, e.g., gcc -fwrapv */
 static Fq Fq_freeze(int32 x) {
-    x -= q * ((q18 * x) >> 18);
-    x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    x -= (int32) (q * ((q18 * x) >> 18));
+    x -= (int32) (q * ((q27 * x + 67108864) >> 27));
+    return (Fq) x;
 }
 
 /* works for all uint32 x */
 static Fq Fq_bigfreeze(uint32 x) {
-    x -= q * ((x * (uint64)q31) >> 31);
-    x -= q * ((x * (uint64)q31) >> 31);
+    x -= (uint32) (q * ((x * (uint64)q31) >> 31));
+    x -= (uint32) (q * ((x * (uint64)q31) >> 31));
     x -= q;
     x += (-(x >> 31)) & (uint32)q;
-    return x;
+    return (Fq) x;
 }
 
 /* ----- Top and Right */
 
 static int8 Top(Fq C) {
-    return (tau1 * (int32)(C + tau0) + 16384) >> 15;
+    return (int8) ((tau1 * (int32)(C + tau0) + 16384) >> 15);
 }
 
 static Fq Right(int8 T) {
@@ -88,7 +88,7 @@ static void Short_fromlist(small *out, const uint32 *in) {
     }
     PQCLEAN_NTRULPR653_CLEAN_crypto_sort_uint32(L, ppadsort);
     for (i = 0; i < p; ++i) {
-        out[i] = (L[i] & 3) - 1;
+        out[i] = (small) ((L[i] & 3) - 1);
     }
 }
 
@@ -99,7 +99,7 @@ static void Short_fromlist(small *out, const uint32 *in) {
 static void Hash(unsigned char *out, const unsigned char *in, int inlen) {
     unsigned char h[64];
     int i;
-    sha512(h, in, inlen);
+    sha512(h, in, (size_t) inlen);
     for (i = 0; i < 32; ++i) {
         out[i] = h[i];
     }
@@ -278,7 +278,7 @@ int PQCLEAN_NTRULPR653_CLEAN_crypto_kem_dec(unsigned char *k, const unsigned cha
             int8 T[I];
             Top_decode(T, c + Rounded_bytes);
             for (i = 0; i < I; ++i) {
-                r[i] = -int16_negative_mask(Fq_freeze(Right(T[i]) - aB[i] + 4 * w + 1));
+                r[i] = (int8) - int16_negative_mask(Fq_freeze(Right(T[i]) - aB[i] + 4 * w + 1));
             }
         }
     }
@@ -289,12 +289,12 @@ int PQCLEAN_NTRULPR653_CLEAN_crypto_kem_dec(unsigned char *k, const unsigned cha
         Hide(cnew, x, r, pk, cache);
         mask = crypto_verify_clen(c, cnew);
         for (i = 0; i < Inputs_bytes; ++i) {
-            x[1 + i] ^= mask & (x[1 + i] ^ rho[i]);
+            x[1 + i] ^= (unsigned char) (mask & (x[1 + i] ^ rho[i]));
         }
         for (i = 0; i < Ciphertexts_bytes + Confirm_bytes; ++i) {
             x[1 + Inputs_bytes + i] = c[i];
         }
-        x[0] = 1 + mask;
+        x[0] = (unsigned char) (1 + mask);
         Hash(k, x, sizeof x);
     }
     return 0;
diff --git a/crypto_kem/ntrulpr761/avx2/Makefile b/crypto_kem/ntrulpr761/avx2/Makefile
index 053dd074..d0da86f6 100644
--- a/crypto_kem/ntrulpr761/avx2/Makefile
+++ b/crypto_kem/ntrulpr761/avx2/Makefile
@@ -4,7 +4,7 @@ LIB=libntrulpr761_avx2.a
 HEADERS=api.h crypto_core_multsntrup761.h crypto_core_multsntrup761_ntt.h crypto_decode_256x16.h crypto_decode_256x2.h crypto_decode_761x1531.h crypto_decode_761x3.h crypto_decode_761xint16.h crypto_decode_761xint32.h crypto_encode_256x16.h crypto_encode_256x2.h crypto_encode_761x1531.h crypto_encode_761x1531round.h crypto_encode_761x3.h crypto_encode_761xint16.h crypto_sort_int32.h crypto_sort_uint32.h crypto_stream_aes256ctr.h crypto_verify_1167.h params.h 
 OBJECTS=crypto_core_multsntrup761.o crypto_core_multsntrup761_ntt.o crypto_decode_256x16.o crypto_decode_256x2.o crypto_decode_761x1531.o crypto_decode_761x3.o crypto_decode_761xint16.o crypto_decode_761xint32.o crypto_encode_256x16.o crypto_encode_256x2.o crypto_encode_761x1531.o crypto_encode_761x1531round.o crypto_encode_761x3.o crypto_encode_761xint16.o crypto_sort_int32.o crypto_sort_uint32.o crypto_stream_aes256ctr.o crypto_verify_1167.o kem.o 
 
-CFLAGS=-O3 -mavx2 -mbmi2 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -std=c99 -I../../../common $(EXTRAFLAGS)
+CFLAGS=-O3 -mavx2 -mbmi2 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -Wconversion -std=c99 -I../../../common $(EXTRAFLAGS)
 
 all: $(LIB)
 
diff --git a/crypto_kem/ntrulpr761/avx2/crypto_core_multsntrup761.c b/crypto_kem/ntrulpr761/avx2/crypto_core_multsntrup761.c
index b38397a3..c5a1ce0d 100644
--- a/crypto_kem/ntrulpr761/avx2/crypto_core_multsntrup761.c
+++ b/crypto_kem/ntrulpr761/avx2/crypto_core_multsntrup761.c
@@ -291,9 +291,9 @@ int PQCLEAN_NTRULPR761_AVX2_crypto_core_multsntrup761(unsigned char *outbytes, c
         store_x16(&f[i], x);
     }
     for (i = 0; i < p; ++i) {
-        int8 gi = kbytes[i];
+        int8 gi = (int8) kbytes[i];
         int8 gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (int16) (gi0 - (gi & (gi0 << 1)));
     }
 
     mult768(fg, f, g);
diff --git a/crypto_kem/ntrulpr761/avx2/crypto_decode_256x2.c b/crypto_kem/ntrulpr761/avx2/crypto_decode_256x2.c
index defc1b76..dd58d199 100644
--- a/crypto_kem/ntrulpr761/avx2/crypto_decode_256x2.c
+++ b/crypto_kem/ntrulpr761/avx2/crypto_decode_256x2.c
@@ -3,7 +3,7 @@
 #include <stdint.h>
 
 #define COPY _mm256_set_epi64x(0x0303030303030303,0x0202020202020202,0x0101010101010101,0x0000000000000000)
-#define MASK _mm256_set1_epi64x(0x8040201008040201)
+#define MASK _mm256_set1_epi64x((int64_t) 0x8040201008040201)
 #define MASK2 _mm256_set1_epi64x(0x0101010101010101)
 
 void PQCLEAN_NTRULPR761_AVX2_crypto_decode_256x2(void *v, const unsigned char *s) {
diff --git a/crypto_kem/ntrulpr761/avx2/crypto_decode_761x1531.c b/crypto_kem/ntrulpr761/avx2/crypto_decode_761x1531.c
index 3b373183..730bd88c 100644
--- a/crypto_kem/ntrulpr761/avx2/crypto_decode_761x1531.c
+++ b/crypto_kem/ntrulpr761/avx2/crypto_decode_761x1531.c
@@ -10,7 +10,7 @@ static inline int16 mullo(int16 x, int16 y) {
 }
 
 static inline int16 mulhi(int16 x, int16 y) {
-    return (x * (int32)y) >> 16;
+    return (int16) ((x * (int32)y) >> 16);
 }
 
 static inline __m256i add(__m256i x, __m256i y) {
@@ -78,7 +78,7 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
     a0 = mulhi(a0, 60) - mulhi(mullo(a0, -28292), 593); /* -297...311 */
     a0 += s[1 * i + 0]; /* -297...566 */
     a0 += (a0 >> 15) & 593; /* 0...592 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, -31055);
 
     /* invalid inputs might need reduction mod 1500 */
@@ -100,7 +100,7 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
         a0 = mulhi(a0, 672) - mulhi(mullo(a0, -2692), 6232); /* -3148...3152 */
         a0 += s[2 * i + 0]; /* -3148...3407 */
         a0 += (a0 >> 15) & 6232; /* 0...6231 */
-        a1 = (a2 << 13) + (s[2 * i + 1] << 5) + ((s[2 * i] - a0) >> 3);
+        a1 = (int16) ((a2 << 13) + (s[2 * i + 1] << 5) + ((s[2 * i] - a0) >> 3));
         a1 = mullo(a1, 12451);
 
         /* invalid inputs might need reduction mod 6232 */
@@ -119,7 +119,7 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
     a0 = mulhi(a0, -476) - mulhi(mullo(a0, -13284), 1263); /* -751...631 */
     a0 += s[1 * i + 0]; /* -751...886 */
     a0 += (a0 >> 15) & 1263; /* 0...1262 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, -22001);
 
     /* invalid inputs might need reduction mod 304 */
@@ -134,7 +134,7 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
         a0 = mulhi(a0, -476) - mulhi(mullo(a0, -13284), 1263); /* -751...631 */
         a0 += s[1 * i + 0]; /* -751...886 */
         a0 += (a0 >> 15) & 1263; /* 0...1262 */
-        a1 = (a2 << 8) + s[i] - a0;
+        a1 = (int16) ((a2 << 8) + s[i] - a0);
         a1 = mullo(a1, -22001);
 
         /* invalid inputs might need reduction mod 1263 */
@@ -155,7 +155,7 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
     a0 = mulhi(a0, 2348) - mulhi(mullo(a0, -1844), 9097); /* -4712...4741 */
     a0 += s[2 * i + 0]; /* -4712...4996 */
     a0 += (a0 >> 15) & 9097; /* 0...9096 */
-    a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+    a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
     a1 = mullo(a1, 17081);
 
     /* invalid inputs might need reduction mod 2188 */
@@ -172,7 +172,7 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
         a0 = mulhi(a0, 2348) - mulhi(mullo(a0, -1844), 9097); /* -4712...4741 */
         a0 += s[2 * i + 0]; /* -4712...4996 */
         a0 += (a0 >> 15) & 9097; /* 0...9096 */
-        a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+        a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
         a1 = mullo(a1, 17081);
 
         /* invalid inputs might need reduction mod 9097 */
@@ -191,7 +191,7 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
     a0 = mulhi(a0, 372) - mulhi(mullo(a0, -10994), 1526); /* -763...856 */
     a0 += s[1 * i + 0]; /* -763...1111 */
     a0 += (a0 >> 15) & 1526; /* 0...1525 */
-    a1 = (a2 << 7) + ((s[i] - a0) >> 1);
+    a1 = (int16) ((a2 << 7) + ((s[i] - a0) >> 1));
     a1 = mullo(a1, -18381);
 
     /* invalid inputs might need reduction mod 367 */
@@ -206,7 +206,7 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
         a0 = mulhi(a0, 372) - mulhi(mullo(a0, -10994), 1526); /* -763...856 */
         a0 += s[1 * i + 0]; /* -763...1111 */
         a0 += (a0 >> 15) & 1526; /* 0...1525 */
-        a1 = (a2 << 7) + ((s[i] - a0) >> 1);
+        a1 = (int16) ((a2 << 7) + ((s[i] - a0) >> 1));
         a1 = mullo(a1, -18381);
 
         /* invalid inputs might need reduction mod 1526 */
@@ -225,7 +225,7 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
     a0 = mulhi(a0, -284) - mulhi(mullo(a0, -26844), 625); /* -384...312 */
     a0 += s[1 * i + 0]; /* -384...567 */
     a0 += (a0 >> 15) & 625; /* 0...624 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, 32401);
 
     /* invalid inputs might need reduction mod 150 */
@@ -276,7 +276,7 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
     a0 = mulhi(a0, 2816) - mulhi(mullo(a0, -2621), 6400); /* -3338...3378 */
     a0 += s[2 * i + 0]; /* -3338...3633 */
     a0 += (a0 >> 15) & 6400; /* 0...6399 */
-    a1 = (a2 << 8) + s[2 * i + 1] + ((s[2 * i] - a0) >> 8);
+    a1 = (int16) ((a2 << 8) + s[2 * i + 1] + ((s[2 * i] - a0) >> 8));
     a1 = mullo(a1, 23593);
 
     /* invalid inputs might need reduction mod 1531 */
@@ -397,7 +397,7 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
 
     /* R1 ------> R0: reconstruct mod 761*[1531] */
 
-    R0[760] = 3 * R1[380] - 2295;
+    R0[760] = (int16) (3 * R1[380] - 2295);
     s -= 380;
     i = 364;
     for (;;) {
diff --git a/crypto_kem/ntrulpr761/avx2/crypto_decode_761xint16.c b/crypto_kem/ntrulpr761/avx2/crypto_decode_761xint16.c
index f72588a9..6c2f717a 100644
--- a/crypto_kem/ntrulpr761/avx2/crypto_decode_761xint16.c
+++ b/crypto_kem/ntrulpr761/avx2/crypto_decode_761xint16.c
@@ -8,8 +8,7 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_decode_761xint16(void *v, const unsigned cha
     for (i = 0; i < 761; ++i) {
         uint16_t u0 = s[0];
         uint16_t u1 = s[1];
-        u1 <<= 8;
-        *x = u0 | u1;
+        *x = (uint16_t) (u0 | (u1 << 8));
         x += 1;
         s += 2;
     }
diff --git a/crypto_kem/ntrulpr761/avx2/crypto_encode_256x16.c b/crypto_kem/ntrulpr761/avx2/crypto_encode_256x16.c
index 3cdf2a1d..073c52e9 100644
--- a/crypto_kem/ntrulpr761/avx2/crypto_encode_256x16.c
+++ b/crypto_kem/ntrulpr761/avx2/crypto_encode_256x16.c
@@ -5,6 +5,6 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_encode_256x16(unsigned char *s, const void *
     const unsigned char *T = v;
     int i;
     for (i = 0; i < 128; ++i) {
-        s[i] = T[2 * i] + (T[2 * i + 1] << 4);
+        s[i] = (unsigned char) (T[2 * i] + (T[2 * i + 1] << 4));
     }
 }
diff --git a/crypto_kem/ntrulpr761/avx2/crypto_encode_256x2.c b/crypto_kem/ntrulpr761/avx2/crypto_encode_256x2.c
index 5bafef06..46c6ae54 100644
--- a/crypto_kem/ntrulpr761/avx2/crypto_encode_256x2.c
+++ b/crypto_kem/ntrulpr761/avx2/crypto_encode_256x2.c
@@ -29,60 +29,60 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_encode_256x2(unsigned char *s, const void *v
     int32_t c5 = _mm256_movemask_epi8(b5);
     int32_t c6 = _mm256_movemask_epi8(b6);
     int32_t c7 = _mm256_movemask_epi8(b7);
-    *s++ = c0;
+    *s++ = (unsigned char) c0;
     c0 >>= 8;
-    *s++ = c0;
+    *s++ = (unsigned char) c0;
     c0 >>= 8;
-    *s++ = c0;
+    *s++ = (unsigned char) c0;
     c0 >>= 8;
-    *s++ = c0;
-    *s++ = c1;
+    *s++ = (unsigned char) c0;
+    *s++ = (unsigned char) c1;
     c1 >>= 8;
-    *s++ = c1;
+    *s++ = (unsigned char) c1;
     c1 >>= 8;
-    *s++ = c1;
+    *s++ = (unsigned char) c1;
     c1 >>= 8;
-    *s++ = c1;
-    *s++ = c2;
+    *s++ = (unsigned char) c1;
+    *s++ = (unsigned char) c2;
     c2 >>= 8;
-    *s++ = c2;
+    *s++ = (unsigned char) c2;
     c2 >>= 8;
-    *s++ = c2;
+    *s++ = (unsigned char) c2;
     c2 >>= 8;
-    *s++ = c2;
-    *s++ = c3;
+    *s++ = (unsigned char) c2;
+    *s++ = (unsigned char) c3;
     c3 >>= 8;
-    *s++ = c3;
+    *s++ = (unsigned char) c3;
     c3 >>= 8;
-    *s++ = c3;
+    *s++ = (unsigned char) c3;
     c3 >>= 8;
-    *s++ = c3;
-    *s++ = c4;
+    *s++ = (unsigned char) c3;
+    *s++ = (unsigned char) c4;
     c4 >>= 8;
-    *s++ = c4;
+    *s++ = (unsigned char) c4;
     c4 >>= 8;
-    *s++ = c4;
+    *s++ = (unsigned char) c4;
     c4 >>= 8;
-    *s++ = c4;
-    *s++ = c5;
+    *s++ = (unsigned char) c4;
+    *s++ = (unsigned char) c5;
     c5 >>= 8;
-    *s++ = c5;
+    *s++ = (unsigned char) c5;
     c5 >>= 8;
-    *s++ = c5;
+    *s++ = (unsigned char) c5;
     c5 >>= 8;
-    *s++ = c5;
-    *s++ = c6;
+    *s++ = (unsigned char) c5;
+    *s++ = (unsigned char) c6;
     c6 >>= 8;
-    *s++ = c6;
+    *s++ = (unsigned char) c6;
     c6 >>= 8;
-    *s++ = c6;
+    *s++ = (unsigned char) c6;
     c6 >>= 8;
-    *s++ = c6;
-    *s++ = c7;
+    *s++ = (unsigned char) c6;
+    *s++ = (unsigned char) c7;
     c7 >>= 8;
-    *s++ = c7;
+    *s++ = (unsigned char) c7;
     c7 >>= 8;
-    *s++ = c7;
+    *s++ = (unsigned char) c7;
     c7 >>= 8;
-    *s++ = c7;
+    *s++ = (unsigned char) c7;
 }
diff --git a/crypto_kem/ntrulpr761/avx2/crypto_encode_761x1531.c b/crypto_kem/ntrulpr761/avx2/crypto_encode_761x1531.c
index 8726b5ba..b9cb299e 100644
--- a/crypto_kem/ntrulpr761/avx2/crypto_encode_761x1531.c
+++ b/crypto_kem/ntrulpr761/avx2/crypto_encode_761x1531.c
@@ -42,26 +42,26 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_encode_761x1531(unsigned char *out, const vo
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
-    R[380] = (((R0[760] + 2295) & 16383) * 10923) >> 15;
+    R[380] = (uint16) ((((R0[760] + 2295) & 16383) * 10923) >> 15);
 
     reading = (uint16 *) R;
     writing = R;
@@ -124,22 +124,22 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_encode_761x1531(unsigned char *out, const vo
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -195,22 +195,22 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_encode_761x1531(unsigned char *out, const vo
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -237,22 +237,22 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_encode_761x1531(unsigned char *out, const vo
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -261,41 +261,41 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_encode_761x1531(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)9097;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 3; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1263;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)6232;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)593;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/ntrulpr761/avx2/crypto_encode_761x1531round.c b/crypto_kem/ntrulpr761/avx2/crypto_encode_761x1531round.c
index e1f96889..bd73145b 100644
--- a/crypto_kem/ntrulpr761/avx2/crypto_encode_761x1531round.c
+++ b/crypto_kem/ntrulpr761/avx2/crypto_encode_761x1531round.c
@@ -44,26 +44,26 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_encode_761x1531round(unsigned char *out, con
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
-    R[380] = (((3 * ((10923 * R0[760] + 16384) >> 15) + 2295) & 16383) * 10923) >> 15;
+    R[380] = (uint16) ((((3 * ((10923 * R0[760] + 16384) >> 15) + 2295) & 16383) * 10923) >> 15);
 
     reading = (uint16 *) R;
     writing = R;
@@ -126,22 +126,22 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_encode_761x1531round(unsigned char *out, con
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -197,22 +197,22 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_encode_761x1531round(unsigned char *out, con
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -239,22 +239,22 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_encode_761x1531round(unsigned char *out, con
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -263,41 +263,41 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_encode_761x1531round(unsigned char *out, con
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)9097;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 3; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1263;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)6232;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)593;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/ntrulpr761/avx2/crypto_encode_761xint16.c b/crypto_kem/ntrulpr761/avx2/crypto_encode_761xint16.c
index cc86a098..8894a09d 100644
--- a/crypto_kem/ntrulpr761/avx2/crypto_encode_761xint16.c
+++ b/crypto_kem/ntrulpr761/avx2/crypto_encode_761xint16.c
@@ -7,7 +7,7 @@ void PQCLEAN_NTRULPR761_AVX2_crypto_encode_761xint16(unsigned char *s, const voi
 
     for (i = 0; i < 761; ++i) {
         uint16_t u = *x++;
-        *s++ = u;
-        *s++ = u >> 8;
+        *s++ = (unsigned char) u;
+        *s++ = (unsigned char) (u >> 8);
     }
 }
diff --git a/crypto_kem/ntrulpr761/avx2/crypto_sort_int32.c b/crypto_kem/ntrulpr761/avx2/crypto_sort_int32.c
index ac82d1a4..14a400a7 100644
--- a/crypto_kem/ntrulpr761/avx2/crypto_sort_int32.c
+++ b/crypto_kem/ntrulpr761/avx2/crypto_sort_int32.c
@@ -44,7 +44,7 @@ static void minmax_vector(int32 *x, int32 *y, size_t n) {
         int32x8_MINMAX(x0, y0);
         int32x8_store(x + n - 8, x0);
         int32x8_store(y + n - 8, y0);
-        n &= ~7;
+        n &= ~(size_t) 7;
     }
     do {
         int32x8 x0 = int32x8_load(x);
diff --git a/crypto_kem/ntrulpr761/avx2/crypto_verify_1167.c b/crypto_kem/ntrulpr761/avx2/crypto_verify_1167.c
index 17c1da57..5fa3f002 100644
--- a/crypto_kem/ntrulpr761/avx2/crypto_verify_1167.c
+++ b/crypto_kem/ntrulpr761/avx2/crypto_verify_1167.c
@@ -27,10 +27,10 @@ int PQCLEAN_NTRULPR761_AVX2_crypto_verify_1167(const unsigned char *x, const uns
     diff |= _mm256_srli_epi32(diff, 16);
     diff |= _mm256_srli_epi64(diff, 32);
 
-    differentbits = _mm256_extract_epi8(diff, 0);
-    differentbits |= _mm256_extract_epi8(diff, 8);
-    differentbits |= _mm256_extract_epi8(diff, 16);
-    differentbits |= _mm256_extract_epi8(diff, 24);
+    differentbits = (unsigned int) _mm256_extract_epi8(diff, 0);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 8);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 16);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 24);
 
     return (int) (1 & ((differentbits - 1) >> 8)) - 1;
 }
diff --git a/crypto_kem/ntrulpr761/avx2/kem.c b/crypto_kem/ntrulpr761/avx2/kem.c
index e42cf7d0..cedf347e 100644
--- a/crypto_kem/ntrulpr761/avx2/kem.c
+++ b/crypto_kem/ntrulpr761/avx2/kem.c
@@ -18,7 +18,7 @@
 
 /* return -1 if x<0; otherwise return 0 */
 static int int16_negative_mask(int16 x) {
-    uint16 u = x;
+    uint16 u = (uint16) x;
     u >>= 15;
     return -(int) u;
     /* alternative with gcc -fwrapv: */
@@ -38,24 +38,24 @@ typedef int16 Fq;
 /* works for -14000000 < x < 14000000 if q in 4591, 4621, 5167 */
 /* assumes twos complement; use, e.g., gcc -fwrapv */
 static Fq Fq_freeze(int32 x) {
-    x -= q * ((q18 * x) >> 18);
-    x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    x -= (int32) (q * ((q18 * x) >> 18));
+    x -= (int32) (q * ((q27 * x + 67108864) >> 27));
+    return (Fq) x;
 }
 
 /* works for all uint32 x */
 static Fq Fq_bigfreeze(uint32 x) {
-    x -= q * ((x * (uint64)q31) >> 31);
-    x -= q * ((x * (uint64)q31) >> 31);
+    x -= (uint32) (q * ((x * (uint64)q31) >> 31));
+    x -= (uint32) (q * ((x * (uint64)q31) >> 31));
     x -= q;
     x += (-(x >> 31)) & (uint32)q;
-    return x;
+    return (Fq) x;
 }
 
 /* ----- Top and Right */
 
 static int8 Top(Fq C) {
-    return (tau1 * (int32)(C + tau0) + 16384) >> 15;
+    return (int8) ((tau1 * (int32)(C + tau0) + 16384) >> 15);
 }
 
 static Fq Right(int8 T) {
@@ -88,7 +88,7 @@ static void Short_fromlist(small *out, const uint32 *in) {
     }
     PQCLEAN_NTRULPR761_AVX2_crypto_sort_uint32(L, ppadsort);
     for (i = 0; i < p; ++i) {
-        out[i] = (L[i] & 3) - 1;
+        out[i] = (small) ((L[i] & 3) - 1);
     }
 }
 
@@ -99,7 +99,7 @@ static void Short_fromlist(small *out, const uint32 *in) {
 static void Hash(unsigned char *out, const unsigned char *in, int inlen) {
     unsigned char h[64];
     int i;
-    sha512(h, in, inlen);
+    sha512(h, in, (size_t) inlen);
     for (i = 0; i < 32; ++i) {
         out[i] = h[i];
     }
@@ -278,7 +278,7 @@ int PQCLEAN_NTRULPR761_AVX2_crypto_kem_dec(unsigned char *k, const unsigned char
             int8 T[I];
             Top_decode(T, c + Rounded_bytes);
             for (i = 0; i < I; ++i) {
-                r[i] = -int16_negative_mask(Fq_freeze(Right(T[i]) - aB[i] + 4 * w + 1));
+                r[i] = (int8) - int16_negative_mask(Fq_freeze(Right(T[i]) - aB[i] + 4 * w + 1));
             }
         }
     }
@@ -289,12 +289,12 @@ int PQCLEAN_NTRULPR761_AVX2_crypto_kem_dec(unsigned char *k, const unsigned char
         Hide(cnew, x, r, pk, cache);
         mask = crypto_verify_clen(c, cnew);
         for (i = 0; i < Inputs_bytes; ++i) {
-            x[1 + i] ^= mask & (x[1 + i] ^ rho[i]);
+            x[1 + i] ^= (unsigned char) (mask & (x[1 + i] ^ rho[i]));
         }
         for (i = 0; i < Ciphertexts_bytes + Confirm_bytes; ++i) {
             x[1 + Inputs_bytes + i] = c[i];
         }
-        x[0] = 1 + mask;
+        x[0] = (unsigned char) (1 + mask);
         Hash(k, x, sizeof x);
     }
     return 0;
diff --git a/crypto_kem/ntrulpr761/clean/Makefile b/crypto_kem/ntrulpr761/clean/Makefile
index b1efe00b..5a6bbbc5 100644
--- a/crypto_kem/ntrulpr761/clean/Makefile
+++ b/crypto_kem/ntrulpr761/clean/Makefile
@@ -4,7 +4,7 @@ LIB=libntrulpr761_clean.a
 HEADERS=api.h crypto_core_multsntrup761.h crypto_decode_256x16.h crypto_decode_256x2.h crypto_decode_761x1531.h crypto_decode_761x3.h crypto_decode_761xint16.h crypto_decode_761xint32.h crypto_encode_256x16.h crypto_encode_256x2.h crypto_encode_761x1531.h crypto_encode_761x1531round.h crypto_encode_761x3.h crypto_encode_761xint16.h crypto_sort_int32.h crypto_sort_uint32.h crypto_stream_aes256ctr.h crypto_verify_1167.h params.h 
 OBJECTS=crypto_core_multsntrup761.o crypto_decode_256x16.o crypto_decode_256x2.o crypto_decode_761x1531.o crypto_decode_761x3.o crypto_decode_761xint16.o crypto_decode_761xint32.o crypto_encode_256x16.o crypto_encode_256x2.o crypto_encode_761x1531.o crypto_encode_761x1531round.o crypto_encode_761x3.o crypto_encode_761xint16.o crypto_sort_int32.o crypto_sort_uint32.o crypto_stream_aes256ctr.o crypto_verify_1167.o kem.o 
 
-CFLAGS=-O3 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -std=c99 -I../../../common $(EXTRAFLAGS)
+CFLAGS=-O3 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -Wconversion -std=c99 -I../../../common $(EXTRAFLAGS)
 
 all: $(LIB)
 
diff --git a/crypto_kem/ntrulpr761/clean/crypto_core_multsntrup761.c b/crypto_kem/ntrulpr761/clean/crypto_core_multsntrup761.c
index 6fadd821..4c5086f5 100644
--- a/crypto_kem/ntrulpr761/clean/crypto_core_multsntrup761.c
+++ b/crypto_kem/ntrulpr761/clean/crypto_core_multsntrup761.c
@@ -14,7 +14,7 @@ typedef int16 Fq;
 static Fq Fq_freeze(int32 x) {
     x -= q * ((q18 * x) >> 18);
     x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    return (Fq) x;
 }
 
 int PQCLEAN_NTRULPR761_CLEAN_crypto_core_multsntrup761(unsigned char *outbytes, const unsigned char *inbytes, const unsigned char *kbytes) {
@@ -30,9 +30,9 @@ int PQCLEAN_NTRULPR761_CLEAN_crypto_core_multsntrup761(unsigned char *outbytes,
     }
 
     for (i = 0; i < p; ++i) {
-        small gi = kbytes[i];
+        small gi = (small) kbytes[i];
         small gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (small) (gi0 - (gi & (gi0 << 1)));
     }
 
     for (i = 0; i < p; ++i) {
diff --git a/crypto_kem/ntrulpr761/clean/crypto_decode_761x1531.c b/crypto_kem/ntrulpr761/clean/crypto_decode_761x1531.c
index fe2c1adb..904358f0 100644
--- a/crypto_kem/ntrulpr761/clean/crypto_decode_761x1531.c
+++ b/crypto_kem/ntrulpr761/clean/crypto_decode_761x1531.c
@@ -30,7 +30,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
 
     *q = 0;
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 2^31 qpart <= xv <= 2^31 qpart + 2^31-1 */
     /* 2^31 qpart m <= xvm <= 2^31 qpart m + (2^31-1)m */
     /* 2^31 qpart m <= 2^31 x <= 2^31 qpart m + (2^31-1)m + x(m-1) */
@@ -42,7 +42,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += qpart;
     /* x <= 49146 */
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 0 <= newx <= (1-1/2^31)m + x(m-1)/2^31 */
     /* 0 <= newx <= m + 49146(2^14-1)/2^31 */
     /* 0 <= newx <= m + 0.4 */
@@ -59,7 +59,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += mask;
     /* x < m */
 
-    *r = x;
+    *r = (uint16) x;
 }
 
 static uint16 uint32_mod_uint14(uint32 x, uint16 m) {
@@ -81,14 +81,14 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_decode_761x1531(void *v, const unsigned cha
     r1 = (r1 << 8) | *--s;
     r1 = (r1 << 8) | *--s;
     r1 = uint32_mod_uint14(r1, 3475); /* needed only for invalid inputs */
-    R10[0] = r1;
+    R10[0] = (uint16) r1;
 
     r2 = R10[0];
     r2 = (r2 << 8) | *--s;
     uint32_divmod_uint14(&r1, &r0, r2, 593);
     R9[0] = r0;
     r1 = uint32_mod_uint14(r1, 1500); /* needed only for invalid inputs */
-    R9[1] = r1;
+    R9[1] = (uint16) r1;
 
     R8[2] = R9[1];
     r2 = R9[0];
@@ -97,21 +97,21 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_decode_761x1531(void *v, const unsigned cha
     uint32_divmod_uint14(&r1, &r0, r2, 6232);
     R8[0] = r0;
     r1 = uint32_mod_uint14(r1, 6232); /* needed only for invalid inputs */
-    R8[1] = r1;
+    R8[1] = (uint16) r1;
 
     r2 = R8[2];
     r2 = (r2 << 8) | *--s;
     uint32_divmod_uint14(&r1, &r0, r2, 1263);
     R7[4] = r0;
     r1 = uint32_mod_uint14(r1, 304); /* needed only for invalid inputs */
-    R7[5] = r1;
+    R7[5] = (uint16) r1;
     for (i = 1; i >= 0; --i) {
         r2 = R8[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 1263);
         R7[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 1263); /* needed only for invalid inputs */
-        R7[2 * i + 1] = r1;
+        R7[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R7[5];
@@ -120,7 +120,7 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_decode_761x1531(void *v, const unsigned cha
     uint32_divmod_uint14(&r1, &r0, r2, 9097);
     R6[10] = r0;
     r1 = uint32_mod_uint14(r1, 2188); /* needed only for invalid inputs */
-    R6[11] = r1;
+    R6[11] = (uint16) r1;
     for (i = 4; i >= 0; --i) {
         r2 = R7[i];
         r2 = (r2 << 8) | *--s;
@@ -128,7 +128,7 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_decode_761x1531(void *v, const unsigned cha
         uint32_divmod_uint14(&r1, &r0, r2, 9097);
         R6[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 9097); /* needed only for invalid inputs */
-        R6[2 * i + 1] = r1;
+        R6[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R6[11];
@@ -136,14 +136,14 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_decode_761x1531(void *v, const unsigned cha
     uint32_divmod_uint14(&r1, &r0, r2, 1526);
     R5[22] = r0;
     r1 = uint32_mod_uint14(r1, 367); /* needed only for invalid inputs */
-    R5[23] = r1;
+    R5[23] = (uint16) r1;
     for (i = 10; i >= 0; --i) {
         r2 = R6[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 1526);
         R5[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 1526); /* needed only for invalid inputs */
-        R5[2 * i + 1] = r1;
+        R5[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R5[23];
@@ -151,14 +151,14 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_decode_761x1531(void *v, const unsigned cha
     uint32_divmod_uint14(&r1, &r0, r2, 625);
     R4[46] = r0;
     r1 = uint32_mod_uint14(r1, 150); /* needed only for invalid inputs */
-    R4[47] = r1;
+    R4[47] = (uint16) r1;
     for (i = 22; i >= 0; --i) {
         r2 = R5[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 625);
         R4[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 625); /* needed only for invalid inputs */
-        R4[2 * i + 1] = r1;
+        R4[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R4[47];
@@ -167,7 +167,7 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_decode_761x1531(void *v, const unsigned cha
     uint32_divmod_uint14(&r1, &r0, r2, 6400);
     R3[94] = r0;
     r1 = uint32_mod_uint14(r1, 1531); /* needed only for invalid inputs */
-    R3[95] = r1;
+    R3[95] = (uint16) r1;
     for (i = 46; i >= 0; --i) {
         r2 = R4[i];
         r2 = (r2 << 8) | *--s;
@@ -175,7 +175,7 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_decode_761x1531(void *v, const unsigned cha
         uint32_divmod_uint14(&r1, &r0, r2, 6400);
         R3[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 6400); /* needed only for invalid inputs */
-        R3[2 * i + 1] = r1;
+        R3[2 * i + 1] = (uint16) r1;
     }
 
     R2[190] = R3[95];
@@ -185,7 +185,7 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_decode_761x1531(void *v, const unsigned cha
         uint32_divmod_uint14(&r1, &r0, r2, 1280);
         R2[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 1280); /* needed only for invalid inputs */
-        R2[2 * i + 1] = r1;
+        R2[2 * i + 1] = (uint16) r1;
     }
 
     R1[380] = R2[190];
@@ -196,16 +196,16 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_decode_761x1531(void *v, const unsigned cha
         uint32_divmod_uint14(&r1, &r0, r2, 9157);
         R1[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 9157); /* needed only for invalid inputs */
-        R1[2 * i + 1] = r1;
+        R1[2 * i + 1] = (uint16) r1;
     }
 
-    R0[760] = 3 * R1[380] - 2295;
+    R0[760] = (int16) (3 * R1[380] - 2295);
     for (i = 379; i >= 0; --i) {
         r2 = R1[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 1531);
-        R0[2 * i] = 3 * r0 - 2295;
+        R0[2 * i] = (int16) (3 * r0 - 2295);
         r1 = uint32_mod_uint14(r1, 1531); /* needed only for invalid inputs */
-        R0[2 * i + 1] = 3 * r1 - 2295;
+        R0[2 * i + 1] = (int16) (3 * r1 - 2295);
     }
 }
diff --git a/crypto_kem/ntrulpr761/clean/crypto_decode_761xint16.c b/crypto_kem/ntrulpr761/clean/crypto_decode_761xint16.c
index d13db387..b506fcc9 100644
--- a/crypto_kem/ntrulpr761/clean/crypto_decode_761xint16.c
+++ b/crypto_kem/ntrulpr761/clean/crypto_decode_761xint16.c
@@ -8,8 +8,7 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_decode_761xint16(void *v, const unsigned ch
     for (i = 0; i < 761; ++i) {
         uint16_t u0 = s[0];
         uint16_t u1 = s[1];
-        u1 <<= 8;
-        *x = u0 | u1;
+        *x = (uint16_t) (u0 | (u1 << 8));
         x += 1;
         s += 2;
     }
diff --git a/crypto_kem/ntrulpr761/clean/crypto_encode_256x16.c b/crypto_kem/ntrulpr761/clean/crypto_encode_256x16.c
index c3f825b9..af79cc4f 100644
--- a/crypto_kem/ntrulpr761/clean/crypto_encode_256x16.c
+++ b/crypto_kem/ntrulpr761/clean/crypto_encode_256x16.c
@@ -5,6 +5,6 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_encode_256x16(unsigned char *s, const void
     const unsigned char *T = v;
     int i;
     for (i = 0; i < 128; ++i) {
-        s[i] = T[2 * i] + (T[2 * i + 1] << 4);
+        s[i] = (unsigned char) (T[2 * i] + (T[2 * i + 1] << 4));
     }
 }
diff --git a/crypto_kem/ntrulpr761/clean/crypto_encode_256x2.c b/crypto_kem/ntrulpr761/clean/crypto_encode_256x2.c
index ff31479e..51701ea5 100644
--- a/crypto_kem/ntrulpr761/clean/crypto_encode_256x2.c
+++ b/crypto_kem/ntrulpr761/clean/crypto_encode_256x2.c
@@ -8,6 +8,6 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_encode_256x2(unsigned char *s, const void *
         s[i] = 0;
     }
     for (i = 0; i < 256; ++i) {
-        s[i >> 3] |= (r[i] & 1) << (i & 7);
+        s[i >> 3] |= (unsigned char) ((r[i] & 1) << (i & 7));
     }
 }
diff --git a/crypto_kem/ntrulpr761/clean/crypto_encode_761x1531.c b/crypto_kem/ntrulpr761/clean/crypto_encode_761x1531.c
index 74243957..e8750688 100644
--- a/crypto_kem/ntrulpr761/clean/crypto_encode_761x1531.c
+++ b/crypto_kem/ntrulpr761/clean/crypto_encode_761x1531.c
@@ -15,24 +15,24 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_encode_761x1531(unsigned char *out, const v
     uint32 r2;
 
     for (i = 0; i < 380; ++i) {
-        r0 = (((R0[2 * i] + 2295) & 16383) * 10923) >> 15;
-        r1 = (((R0[2 * i + 1] + 2295) & 16383) * 10923) >> 15;
+        r0 = (uint16) ((((R0[2 * i] + 2295) & 16383) * 10923) >> 15);
+        r1 = (uint16) ((((R0[2 * i + 1] + 2295) & 16383) * 10923) >> 15);
         r2 = r0 + r1 * (uint32)1531;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
-    R[380] = (((R0[760] + 2295) & 16383) * 10923) >> 15;
+    R[380] = (uint16) ((((R0[760] + 2295) & 16383) * 10923) >> 15);
 
     for (i = 0; i < 190; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)9157;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[190] = R[380];
 
@@ -40,9 +40,9 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_encode_761x1531(unsigned char *out, const v
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1280;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[95] = R[190];
 
@@ -50,70 +50,70 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_encode_761x1531(unsigned char *out, const v
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)6400;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 24; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)625;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 12; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1526;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 6; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)9097;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 3; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1263;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)6232;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)593;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/ntrulpr761/clean/crypto_encode_761x1531round.c b/crypto_kem/ntrulpr761/clean/crypto_encode_761x1531round.c
index 101283b5..eefb4275 100644
--- a/crypto_kem/ntrulpr761/clean/crypto_encode_761x1531round.c
+++ b/crypto_kem/ntrulpr761/clean/crypto_encode_761x1531round.c
@@ -11,7 +11,7 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_encode_761x1531round(unsigned char *out, co
     int i;
 
     for (i = 0; i < p; ++i) {
-        x[i] = 3 * ((10923 * a[i] + 16384) >> 15);
+        x[i] = (int16) (3 * ((10923 * a[i] + 16384) >> 15));
     }
     PQCLEAN_NTRULPR761_CLEAN_crypto_encode_761x1531(out, x);
 }
diff --git a/crypto_kem/ntrulpr761/clean/crypto_encode_761x3.c b/crypto_kem/ntrulpr761/clean/crypto_encode_761x3.c
index 53cf0e21..7f9bd4d4 100644
--- a/crypto_kem/ntrulpr761/clean/crypto_encode_761x3.c
+++ b/crypto_kem/ntrulpr761/clean/crypto_encode_761x3.c
@@ -11,9 +11,9 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_encode_761x3(unsigned char *s, const void *
 
     for (i = 0; i < p / 4; ++i) {
         x = *f++ + 1;
-        x += (*f++ + 1) << 2;
-        x += (*f++ + 1) << 4;
-        x += (*f++ + 1) << 6;
+        x += (uint8) ((*f++ + 1) << 2);
+        x += (uint8) ((*f++ + 1) << 4);
+        x += (uint8) ((*f++ + 1) << 6);
         *s++ = x;
     }
     x = *f++ + 1;
diff --git a/crypto_kem/ntrulpr761/clean/crypto_encode_761xint16.c b/crypto_kem/ntrulpr761/clean/crypto_encode_761xint16.c
index ec3d1541..8cbb2e9f 100644
--- a/crypto_kem/ntrulpr761/clean/crypto_encode_761xint16.c
+++ b/crypto_kem/ntrulpr761/clean/crypto_encode_761xint16.c
@@ -7,7 +7,7 @@ void PQCLEAN_NTRULPR761_CLEAN_crypto_encode_761xint16(unsigned char *s, const vo
 
     for (i = 0; i < 761; ++i) {
         uint16_t u = *x++;
-        *s++ = u;
-        *s++ = u >> 8;
+        *s++ = (unsigned char) u;
+        *s++ = (unsigned char) (u >> 8);
     }
 }
diff --git a/crypto_kem/ntrulpr761/clean/kem.c b/crypto_kem/ntrulpr761/clean/kem.c
index 16f24b4a..b3c55589 100644
--- a/crypto_kem/ntrulpr761/clean/kem.c
+++ b/crypto_kem/ntrulpr761/clean/kem.c
@@ -18,7 +18,7 @@
 
 /* return -1 if x<0; otherwise return 0 */
 static int int16_negative_mask(int16 x) {
-    uint16 u = x;
+    uint16 u = (uint16) x;
     u >>= 15;
     return -(int) u;
     /* alternative with gcc -fwrapv: */
@@ -38,24 +38,24 @@ typedef int16 Fq;
 /* works for -14000000 < x < 14000000 if q in 4591, 4621, 5167 */
 /* assumes twos complement; use, e.g., gcc -fwrapv */
 static Fq Fq_freeze(int32 x) {
-    x -= q * ((q18 * x) >> 18);
-    x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    x -= (int32) (q * ((q18 * x) >> 18));
+    x -= (int32) (q * ((q27 * x + 67108864) >> 27));
+    return (Fq) x;
 }
 
 /* works for all uint32 x */
 static Fq Fq_bigfreeze(uint32 x) {
-    x -= q * ((x * (uint64)q31) >> 31);
-    x -= q * ((x * (uint64)q31) >> 31);
+    x -= (uint32) (q * ((x * (uint64)q31) >> 31));
+    x -= (uint32) (q * ((x * (uint64)q31) >> 31));
     x -= q;
     x += (-(x >> 31)) & (uint32)q;
-    return x;
+    return (Fq) x;
 }
 
 /* ----- Top and Right */
 
 static int8 Top(Fq C) {
-    return (tau1 * (int32)(C + tau0) + 16384) >> 15;
+    return (int8) ((tau1 * (int32)(C + tau0) + 16384) >> 15);
 }
 
 static Fq Right(int8 T) {
@@ -88,7 +88,7 @@ static void Short_fromlist(small *out, const uint32 *in) {
     }
     PQCLEAN_NTRULPR761_CLEAN_crypto_sort_uint32(L, ppadsort);
     for (i = 0; i < p; ++i) {
-        out[i] = (L[i] & 3) - 1;
+        out[i] = (small) ((L[i] & 3) - 1);
     }
 }
 
@@ -99,7 +99,7 @@ static void Short_fromlist(small *out, const uint32 *in) {
 static void Hash(unsigned char *out, const unsigned char *in, int inlen) {
     unsigned char h[64];
     int i;
-    sha512(h, in, inlen);
+    sha512(h, in, (size_t) inlen);
     for (i = 0; i < 32; ++i) {
         out[i] = h[i];
     }
@@ -278,7 +278,7 @@ int PQCLEAN_NTRULPR761_CLEAN_crypto_kem_dec(unsigned char *k, const unsigned cha
             int8 T[I];
             Top_decode(T, c + Rounded_bytes);
             for (i = 0; i < I; ++i) {
-                r[i] = -int16_negative_mask(Fq_freeze(Right(T[i]) - aB[i] + 4 * w + 1));
+                r[i] = (int8) - int16_negative_mask(Fq_freeze(Right(T[i]) - aB[i] + 4 * w + 1));
             }
         }
     }
@@ -289,12 +289,12 @@ int PQCLEAN_NTRULPR761_CLEAN_crypto_kem_dec(unsigned char *k, const unsigned cha
         Hide(cnew, x, r, pk, cache);
         mask = crypto_verify_clen(c, cnew);
         for (i = 0; i < Inputs_bytes; ++i) {
-            x[1 + i] ^= mask & (x[1 + i] ^ rho[i]);
+            x[1 + i] ^= (unsigned char) (mask & (x[1 + i] ^ rho[i]));
         }
         for (i = 0; i < Ciphertexts_bytes + Confirm_bytes; ++i) {
             x[1 + Inputs_bytes + i] = c[i];
         }
-        x[0] = 1 + mask;
+        x[0] = (unsigned char) (1 + mask);
         Hash(k, x, sizeof x);
     }
     return 0;
diff --git a/crypto_kem/ntrulpr857/avx2/Makefile b/crypto_kem/ntrulpr857/avx2/Makefile
index e4918b62..654e4a83 100644
--- a/crypto_kem/ntrulpr857/avx2/Makefile
+++ b/crypto_kem/ntrulpr857/avx2/Makefile
@@ -4,7 +4,7 @@ LIB=libntrulpr857_avx2.a
 HEADERS=api.h crypto_core_multsntrup857.h crypto_core_multsntrup857_ntt.h crypto_decode_256x16.h crypto_decode_256x2.h crypto_decode_857x1723.h crypto_decode_857x3.h crypto_decode_857xint16.h crypto_decode_857xint32.h crypto_encode_256x16.h crypto_encode_256x2.h crypto_encode_857x1723.h crypto_encode_857x1723round.h crypto_encode_857x3.h crypto_encode_857xint16.h crypto_sort_int32.h crypto_sort_uint32.h crypto_stream_aes256ctr.h crypto_verify_1312.h params.h 
 OBJECTS=crypto_core_multsntrup857.o crypto_core_multsntrup857_ntt.o crypto_decode_256x16.o crypto_decode_256x2.o crypto_decode_857x1723.o crypto_decode_857x3.o crypto_decode_857xint16.o crypto_decode_857xint32.o crypto_encode_256x16.o crypto_encode_256x2.o crypto_encode_857x1723.o crypto_encode_857x1723round.o crypto_encode_857x3.o crypto_encode_857xint16.o crypto_sort_int32.o crypto_sort_uint32.o crypto_stream_aes256ctr.o crypto_verify_1312.o kem.o 
 
-CFLAGS=-O3 -mavx2 -mbmi2 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -std=c99 -I../../../common $(EXTRAFLAGS)
+CFLAGS=-O3 -mavx2 -mbmi2 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -Wconversion -std=c99 -I../../../common $(EXTRAFLAGS)
 
 all: $(LIB)
 
diff --git a/crypto_kem/ntrulpr857/avx2/crypto_core_multsntrup857.c b/crypto_kem/ntrulpr857/avx2/crypto_core_multsntrup857.c
index 674fa8e3..9138df20 100644
--- a/crypto_kem/ntrulpr857/avx2/crypto_core_multsntrup857.c
+++ b/crypto_kem/ntrulpr857/avx2/crypto_core_multsntrup857.c
@@ -398,9 +398,9 @@ int PQCLEAN_NTRULPR857_AVX2_crypto_core_multsntrup857(unsigned char *outbytes, c
         store_x16(&f[i], x);
     }
     for (i = 0; i < p; ++i) {
-        int8 gi = kbytes[i];
+        int8 gi = (int8) kbytes[i];
         int8 gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (int8) (gi0 - (gi & (gi0 << 1)));
     }
 
     mult1024(fg, f, g);
diff --git a/crypto_kem/ntrulpr857/avx2/crypto_decode_256x2.c b/crypto_kem/ntrulpr857/avx2/crypto_decode_256x2.c
index 58051a54..ca8da2c4 100644
--- a/crypto_kem/ntrulpr857/avx2/crypto_decode_256x2.c
+++ b/crypto_kem/ntrulpr857/avx2/crypto_decode_256x2.c
@@ -3,7 +3,7 @@
 #include <stdint.h>
 
 #define COPY _mm256_set_epi64x(0x0303030303030303,0x0202020202020202,0x0101010101010101,0x0000000000000000)
-#define MASK _mm256_set1_epi64x(0x8040201008040201)
+#define MASK _mm256_set1_epi64x((int64_t) 0x8040201008040201)
 #define MASK2 _mm256_set1_epi64x(0x0101010101010101)
 
 void PQCLEAN_NTRULPR857_AVX2_crypto_decode_256x2(void *v, const unsigned char *s) {
diff --git a/crypto_kem/ntrulpr857/avx2/crypto_decode_857x1723.c b/crypto_kem/ntrulpr857/avx2/crypto_decode_857x1723.c
index ff768213..f76abc32 100644
--- a/crypto_kem/ntrulpr857/avx2/crypto_decode_857x1723.c
+++ b/crypto_kem/ntrulpr857/avx2/crypto_decode_857x1723.c
@@ -10,7 +10,7 @@ static inline int16 mullo(int16 x, int16 y) {
 }
 
 static inline int16 mulhi(int16 x, int16 y) {
-    return (x * (int32)y) >> 16;
+    return (int16) ((x * (int32)y) >> 16);
 }
 
 static inline __m256i add(__m256i x, __m256i y) {
@@ -79,7 +79,7 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
     a0 = mulhi(a0, 276) - mulhi(mullo(a0, -22580), 743); /* -374...374 */
     a0 += s[2 * i + 0]; /* -374...629 */
     a0 += (a0 >> 15) & 743; /* 0...742 */
-    a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+    a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
     a1 = mullo(a1, -3881);
 
     /* invalid inputs might need reduction mod 14044 */
@@ -100,7 +100,7 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
     a0 -= 436; /* -670..>37 */
     a0 += (a0 >> 15) & 436; /* -234...435 */
     a0 += (a0 >> 15) & 436; /* 0...435 */
-    a1 = (a2 << 6) + ((s[i] - a0) >> 2);
+    a1 = (int16) ((a2 << 6) + ((s[i] - a0) >> 2));
     a1 = mullo(a1, 2405);
 
     /* invalid inputs might need reduction mod 8246 */
@@ -117,7 +117,7 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
         a0 -= 436; /* -670..>37 */
         a0 += (a0 >> 15) & 436; /* -234...435 */
         a0 += (a0 >> 15) & 436; /* 0...435 */
-        a1 = (a2 << 6) + ((s[i] - a0) >> 2);
+        a1 = (int16) ((a2 << 6) + ((s[i] - a0) >> 2));
         a1 = mullo(a1, 2405);
 
         /* invalid inputs might need reduction mod 436 */
@@ -139,7 +139,7 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
         a0 -= 334; /* -501..>103 */
         a0 += (a0 >> 15) & 334; /* -167...333 */
         a0 += (a0 >> 15) & 334; /* 0...333 */
-        a1 = (a2 << 7) + ((s[i] - a0) >> 1);
+        a1 = (int16) ((a2 << 7) + ((s[i] - a0) >> 1));
         a1 = mullo(a1, -22761);
 
         /* invalid inputs might need reduction mod 334 */
@@ -160,7 +160,7 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
     a0 -= 292; /* -438..>125 */
     a0 += (a0 >> 15) & 292; /* -146...291 */
     a0 += (a0 >> 15) & 292; /* 0...291 */
-    a1 = (a2 << 6) + ((s[i] - a0) >> 2);
+    a1 = (int16) ((a2 << 6) + ((s[i] - a0) >> 2));
     a1 = mullo(a1, -3591);
 
     /* invalid inputs might need reduction mod 7229 */
@@ -177,7 +177,7 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
         a0 -= 292; /* -438..>125 */
         a0 += (a0 >> 15) & 292; /* -146...291 */
         a0 += (a0 >> 15) & 292; /* 0...291 */
-        a1 = (a2 << 6) + ((s[i] - a0) >> 2);
+        a1 = (int16) ((a2 << 6) + ((s[i] - a0) >> 2));
         a1 = mullo(a1, -3591);
 
         /* invalid inputs might need reduction mod 292 */
@@ -199,7 +199,7 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
         a0 -= 273; /* -410..>118 */
         a0 += (a0 >> 15) & 273; /* -137...272 */
         a0 += (a0 >> 15) & 273; /* 0...272 */
-        a1 = (a2 << 8) + s[i] - a0;
+        a1 = (int16) ((a2 << 8) + s[i] - a0);
         a1 = mullo(a1, 4081);
 
         /* invalid inputs might need reduction mod 273 */
@@ -218,7 +218,7 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
     a0 = mulhi(a0, -259) - mulhi(mullo(a0, -3971), 4225); /* -2178...2112 */
     a0 += s[1 * i + 0]; /* -2178...2367 */
     a0 += (a0 >> 15) & 4225; /* 0...4224 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, 12161);
 
     /* invalid inputs might need reduction mod 438 */
@@ -272,7 +272,7 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
     a0 += s[1 * i + 0]; /* -33...287 */
     a0 = mulhi(a0, 16) - mulhi(mullo(a0, -1008), 65); /* -33...32 */
     a0 += (a0 >> 15) & 65; /* 0...64 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, 4033);
 
     /* invalid inputs might need reduction mod 1723 */
@@ -391,7 +391,7 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
 
     /* R1 ------> R0: reconstruct mod 857*[1723] */
 
-    R0[856] = 3 * R1[428] - 2583;
+    R0[856] = (int16) (3 * R1[428] - 2583);
     s -= 428;
     i = 412;
     for (;;) {
diff --git a/crypto_kem/ntrulpr857/avx2/crypto_decode_857xint16.c b/crypto_kem/ntrulpr857/avx2/crypto_decode_857xint16.c
index b44dd5b1..f9dc31e6 100644
--- a/crypto_kem/ntrulpr857/avx2/crypto_decode_857xint16.c
+++ b/crypto_kem/ntrulpr857/avx2/crypto_decode_857xint16.c
@@ -8,8 +8,7 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_decode_857xint16(void *v, const unsigned cha
     for (i = 0; i < 857; ++i) {
         uint16_t u0 = s[0];
         uint16_t u1 = s[1];
-        u1 <<= 8;
-        *x = u0 | u1;
+        *x = (uint16_t) (u0 | (u1 << 8));
         x += 1;
         s += 2;
     }
diff --git a/crypto_kem/ntrulpr857/avx2/crypto_encode_256x16.c b/crypto_kem/ntrulpr857/avx2/crypto_encode_256x16.c
index a60c27c6..a1ead4c1 100644
--- a/crypto_kem/ntrulpr857/avx2/crypto_encode_256x16.c
+++ b/crypto_kem/ntrulpr857/avx2/crypto_encode_256x16.c
@@ -5,6 +5,6 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_encode_256x16(unsigned char *s, const void *
     const unsigned char *T = v;
     int i;
     for (i = 0; i < 128; ++i) {
-        s[i] = T[2 * i] + (T[2 * i + 1] << 4);
+        s[i] = (unsigned char) (T[2 * i] + (T[2 * i + 1] << 4));
     }
 }
diff --git a/crypto_kem/ntrulpr857/avx2/crypto_encode_256x2.c b/crypto_kem/ntrulpr857/avx2/crypto_encode_256x2.c
index 6220e2ab..f24fae0e 100644
--- a/crypto_kem/ntrulpr857/avx2/crypto_encode_256x2.c
+++ b/crypto_kem/ntrulpr857/avx2/crypto_encode_256x2.c
@@ -29,60 +29,60 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_encode_256x2(unsigned char *s, const void *v
     int32_t c5 = _mm256_movemask_epi8(b5);
     int32_t c6 = _mm256_movemask_epi8(b6);
     int32_t c7 = _mm256_movemask_epi8(b7);
-    *s++ = c0;
+    *s++ = (unsigned char) c0;
     c0 >>= 8;
-    *s++ = c0;
+    *s++ = (unsigned char) c0;
     c0 >>= 8;
-    *s++ = c0;
+    *s++ = (unsigned char) c0;
     c0 >>= 8;
-    *s++ = c0;
-    *s++ = c1;
+    *s++ = (unsigned char) c0;
+    *s++ = (unsigned char) c1;
     c1 >>= 8;
-    *s++ = c1;
+    *s++ = (unsigned char) c1;
     c1 >>= 8;
-    *s++ = c1;
+    *s++ = (unsigned char) c1;
     c1 >>= 8;
-    *s++ = c1;
-    *s++ = c2;
+    *s++ = (unsigned char) c1;
+    *s++ = (unsigned char) c2;
     c2 >>= 8;
-    *s++ = c2;
+    *s++ = (unsigned char) c2;
     c2 >>= 8;
-    *s++ = c2;
+    *s++ = (unsigned char) c2;
     c2 >>= 8;
-    *s++ = c2;
-    *s++ = c3;
+    *s++ = (unsigned char) c2;
+    *s++ = (unsigned char) c3;
     c3 >>= 8;
-    *s++ = c3;
+    *s++ = (unsigned char) c3;
     c3 >>= 8;
-    *s++ = c3;
+    *s++ = (unsigned char) c3;
     c3 >>= 8;
-    *s++ = c3;
-    *s++ = c4;
+    *s++ = (unsigned char) c3;
+    *s++ = (unsigned char) c4;
     c4 >>= 8;
-    *s++ = c4;
+    *s++ = (unsigned char) c4;
     c4 >>= 8;
-    *s++ = c4;
+    *s++ = (unsigned char) c4;
     c4 >>= 8;
-    *s++ = c4;
-    *s++ = c5;
+    *s++ = (unsigned char) c4;
+    *s++ = (unsigned char) c5;
     c5 >>= 8;
-    *s++ = c5;
+    *s++ = (unsigned char) c5;
     c5 >>= 8;
-    *s++ = c5;
+    *s++ = (unsigned char) c5;
     c5 >>= 8;
-    *s++ = c5;
-    *s++ = c6;
+    *s++ = (unsigned char) c5;
+    *s++ = (unsigned char) c6;
     c6 >>= 8;
-    *s++ = c6;
+    *s++ = (unsigned char) c6;
     c6 >>= 8;
-    *s++ = c6;
+    *s++ = (unsigned char) c6;
     c6 >>= 8;
-    *s++ = c6;
-    *s++ = c7;
+    *s++ = (unsigned char) c6;
+    *s++ = (unsigned char) c7;
     c7 >>= 8;
-    *s++ = c7;
+    *s++ = (unsigned char) c7;
     c7 >>= 8;
-    *s++ = c7;
+    *s++ = (unsigned char) c7;
     c7 >>= 8;
-    *s++ = c7;
+    *s++ = (unsigned char) c7;
 }
diff --git a/crypto_kem/ntrulpr857/avx2/crypto_encode_857x1723.c b/crypto_kem/ntrulpr857/avx2/crypto_encode_857x1723.c
index 0fce803b..0ea0103d 100644
--- a/crypto_kem/ntrulpr857/avx2/crypto_encode_857x1723.c
+++ b/crypto_kem/ntrulpr857/avx2/crypto_encode_857x1723.c
@@ -42,26 +42,26 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_encode_857x1723(unsigned char *out, const vo
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
-    R[428] = (((R0[856] + 2583) & 16383) * 10923) >> 15;
+    R[428] = (uint16) ((((R0[856] + 2583) & 16383) * 10923) >> 15);
 
     reading = (uint16 *) R;
     writing = R;
@@ -145,14 +145,14 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_encode_857x1723(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)65;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[106];
     r1 = R[107];
     r2 = r0 + r1 * (uint32)65;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[53] = r2;
+    R[53] = (uint16) r2;
 
     reading = (uint16 *) R;
     writing = R;
@@ -194,9 +194,9 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_encode_857x1723(unsigned char *out, const vo
     r0 = R[52];
     r1 = R[53];
     r2 = r0 + r1 * (uint32)4225;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[26] = r2;
+    R[26] = (uint16) r2;
 
     reading = (uint16 *) R;
     writing = R;
@@ -220,22 +220,22 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_encode_857x1723(unsigned char *out, const vo
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -245,18 +245,18 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_encode_857x1723(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)292;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 3; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)334;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[3] = R[6];
 
@@ -264,20 +264,20 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_encode_857x1723(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)436;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)743;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/ntrulpr857/avx2/crypto_encode_857x1723round.c b/crypto_kem/ntrulpr857/avx2/crypto_encode_857x1723round.c
index 48343d4f..946000c0 100644
--- a/crypto_kem/ntrulpr857/avx2/crypto_encode_857x1723round.c
+++ b/crypto_kem/ntrulpr857/avx2/crypto_encode_857x1723round.c
@@ -44,26 +44,26 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_encode_857x1723round(unsigned char *out, con
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
-    R[428] = (((3 * ((10923 * R0[856] + 16384) >> 15) + 2583) & 16383) * 10923) >> 15;
+    R[428] = (uint16) ((((3 * ((10923 * R0[856] + 16384) >> 15) + 2583) & 16383) * 10923) >> 15);
 
     reading = (uint16 *) R;
     writing = R;
@@ -147,14 +147,14 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_encode_857x1723round(unsigned char *out, con
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)65;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[106];
     r1 = R[107];
     r2 = r0 + r1 * (uint32)65;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[53] = r2;
+    R[53] = (uint16) r2;
 
     reading = (uint16 *) R;
     writing = R;
@@ -196,9 +196,9 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_encode_857x1723round(unsigned char *out, con
     r0 = R[52];
     r1 = R[53];
     r2 = r0 + r1 * (uint32)4225;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[26] = r2;
+    R[26] = (uint16) r2;
 
     reading = (uint16 *) R;
     writing = R;
@@ -222,22 +222,22 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_encode_857x1723round(unsigned char *out, con
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -247,18 +247,18 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_encode_857x1723round(unsigned char *out, con
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)292;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 3; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)334;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[3] = R[6];
 
@@ -266,20 +266,20 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_encode_857x1723round(unsigned char *out, con
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)436;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)743;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/ntrulpr857/avx2/crypto_encode_857xint16.c b/crypto_kem/ntrulpr857/avx2/crypto_encode_857xint16.c
index 136c7990..61cda598 100644
--- a/crypto_kem/ntrulpr857/avx2/crypto_encode_857xint16.c
+++ b/crypto_kem/ntrulpr857/avx2/crypto_encode_857xint16.c
@@ -7,7 +7,7 @@ void PQCLEAN_NTRULPR857_AVX2_crypto_encode_857xint16(unsigned char *s, const voi
 
     for (i = 0; i < 857; ++i) {
         uint16_t u = *x++;
-        *s++ = u;
-        *s++ = u >> 8;
+        *s++ = (unsigned char) u;
+        *s++ = (unsigned char) (u >> 8);
     }
 }
diff --git a/crypto_kem/ntrulpr857/avx2/crypto_sort_int32.c b/crypto_kem/ntrulpr857/avx2/crypto_sort_int32.c
index 84544dc6..878ef932 100644
--- a/crypto_kem/ntrulpr857/avx2/crypto_sort_int32.c
+++ b/crypto_kem/ntrulpr857/avx2/crypto_sort_int32.c
@@ -44,7 +44,7 @@ static void minmax_vector(int32 *x, int32 *y, size_t n) {
         int32x8_MINMAX(x0, y0);
         int32x8_store(x + n - 8, x0);
         int32x8_store(y + n - 8, y0);
-        n &= ~7;
+        n &= ~(size_t) 7;
     }
     do {
         int32x8 x0 = int32x8_load(x);
diff --git a/crypto_kem/ntrulpr857/avx2/crypto_verify_1312.c b/crypto_kem/ntrulpr857/avx2/crypto_verify_1312.c
index 950aa37b..53073a5e 100644
--- a/crypto_kem/ntrulpr857/avx2/crypto_verify_1312.c
+++ b/crypto_kem/ntrulpr857/avx2/crypto_verify_1312.c
@@ -27,10 +27,10 @@ int PQCLEAN_NTRULPR857_AVX2_crypto_verify_1312(const unsigned char *x, const uns
     diff |= _mm256_srli_epi32(diff, 16);
     diff |= _mm256_srli_epi64(diff, 32);
 
-    differentbits = _mm256_extract_epi8(diff, 0);
-    differentbits |= _mm256_extract_epi8(diff, 8);
-    differentbits |= _mm256_extract_epi8(diff, 16);
-    differentbits |= _mm256_extract_epi8(diff, 24);
+    differentbits = (unsigned int) _mm256_extract_epi8(diff, 0);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 8);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 16);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 24);
 
     return (int) (1 & ((differentbits - 1) >> 8)) - 1;
 }
diff --git a/crypto_kem/ntrulpr857/avx2/kem.c b/crypto_kem/ntrulpr857/avx2/kem.c
index 4946b7a1..28b44266 100644
--- a/crypto_kem/ntrulpr857/avx2/kem.c
+++ b/crypto_kem/ntrulpr857/avx2/kem.c
@@ -18,7 +18,7 @@
 
 /* return -1 if x<0; otherwise return 0 */
 static int int16_negative_mask(int16 x) {
-    uint16 u = x;
+    uint16 u = (uint16) x;
     u >>= 15;
     return -(int) u;
     /* alternative with gcc -fwrapv: */
@@ -38,24 +38,24 @@ typedef int16 Fq;
 /* works for -14000000 < x < 14000000 if q in 4591, 4621, 5167 */
 /* assumes twos complement; use, e.g., gcc -fwrapv */
 static Fq Fq_freeze(int32 x) {
-    x -= q * ((q18 * x) >> 18);
-    x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    x -= (int32) (q * ((q18 * x) >> 18));
+    x -= (int32) (q * ((q27 * x + 67108864) >> 27));
+    return (Fq) x;
 }
 
 /* works for all uint32 x */
 static Fq Fq_bigfreeze(uint32 x) {
-    x -= q * ((x * (uint64)q31) >> 31);
-    x -= q * ((x * (uint64)q31) >> 31);
+    x -= (uint32) (q * ((x * (uint64)q31) >> 31));
+    x -= (uint32) (q * ((x * (uint64)q31) >> 31));
     x -= q;
     x += (-(x >> 31)) & (uint32)q;
-    return x;
+    return (Fq) x;
 }
 
 /* ----- Top and Right */
 
 static int8 Top(Fq C) {
-    return (tau1 * (int32)(C + tau0) + 16384) >> 15;
+    return (int8) ((tau1 * (int32)(C + tau0) + 16384) >> 15);
 }
 
 static Fq Right(int8 T) {
@@ -88,7 +88,7 @@ static void Short_fromlist(small *out, const uint32 *in) {
     }
     PQCLEAN_NTRULPR857_AVX2_crypto_sort_uint32(L, ppadsort);
     for (i = 0; i < p; ++i) {
-        out[i] = (L[i] & 3) - 1;
+        out[i] = (small) ((L[i] & 3) - 1);
     }
 }
 
@@ -99,7 +99,7 @@ static void Short_fromlist(small *out, const uint32 *in) {
 static void Hash(unsigned char *out, const unsigned char *in, int inlen) {
     unsigned char h[64];
     int i;
-    sha512(h, in, inlen);
+    sha512(h, in, (size_t) inlen);
     for (i = 0; i < 32; ++i) {
         out[i] = h[i];
     }
@@ -278,7 +278,7 @@ int PQCLEAN_NTRULPR857_AVX2_crypto_kem_dec(unsigned char *k, const unsigned char
             int8 T[I];
             Top_decode(T, c + Rounded_bytes);
             for (i = 0; i < I; ++i) {
-                r[i] = -int16_negative_mask(Fq_freeze(Right(T[i]) - aB[i] + 4 * w + 1));
+                r[i] = (int8) - int16_negative_mask(Fq_freeze(Right(T[i]) - aB[i] + 4 * w + 1));
             }
         }
     }
@@ -289,12 +289,12 @@ int PQCLEAN_NTRULPR857_AVX2_crypto_kem_dec(unsigned char *k, const unsigned char
         Hide(cnew, x, r, pk, cache);
         mask = crypto_verify_clen(c, cnew);
         for (i = 0; i < Inputs_bytes; ++i) {
-            x[1 + i] ^= mask & (x[1 + i] ^ rho[i]);
+            x[1 + i] ^= (unsigned char) (mask & (x[1 + i] ^ rho[i]));
         }
         for (i = 0; i < Ciphertexts_bytes + Confirm_bytes; ++i) {
             x[1 + Inputs_bytes + i] = c[i];
         }
-        x[0] = 1 + mask;
+        x[0] = (unsigned char) (1 + mask);
         Hash(k, x, sizeof x);
     }
     return 0;
diff --git a/crypto_kem/ntrulpr857/clean/Makefile b/crypto_kem/ntrulpr857/clean/Makefile
index 62c358a8..9929921e 100644
--- a/crypto_kem/ntrulpr857/clean/Makefile
+++ b/crypto_kem/ntrulpr857/clean/Makefile
@@ -4,7 +4,7 @@ LIB=libntrulpr857_clean.a
 HEADERS=api.h crypto_core_multsntrup857.h crypto_decode_256x16.h crypto_decode_256x2.h crypto_decode_857x1723.h crypto_decode_857x3.h crypto_decode_857xint16.h crypto_decode_857xint32.h crypto_encode_256x16.h crypto_encode_256x2.h crypto_encode_857x1723.h crypto_encode_857x1723round.h crypto_encode_857x3.h crypto_encode_857xint16.h crypto_sort_int32.h crypto_sort_uint32.h crypto_stream_aes256ctr.h crypto_verify_1312.h params.h 
 OBJECTS=crypto_core_multsntrup857.o crypto_decode_256x16.o crypto_decode_256x2.o crypto_decode_857x1723.o crypto_decode_857x3.o crypto_decode_857xint16.o crypto_decode_857xint32.o crypto_encode_256x16.o crypto_encode_256x2.o crypto_encode_857x1723.o crypto_encode_857x1723round.o crypto_encode_857x3.o crypto_encode_857xint16.o crypto_sort_int32.o crypto_sort_uint32.o crypto_stream_aes256ctr.o crypto_verify_1312.o kem.o 
 
-CFLAGS=-O3 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -std=c99 -I../../../common $(EXTRAFLAGS)
+CFLAGS=-O3 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -Wconversion -std=c99 -I../../../common $(EXTRAFLAGS)
 
 all: $(LIB)
 
diff --git a/crypto_kem/ntrulpr857/clean/crypto_core_multsntrup857.c b/crypto_kem/ntrulpr857/clean/crypto_core_multsntrup857.c
index 28c153d4..724c2ea9 100644
--- a/crypto_kem/ntrulpr857/clean/crypto_core_multsntrup857.c
+++ b/crypto_kem/ntrulpr857/clean/crypto_core_multsntrup857.c
@@ -14,7 +14,7 @@ typedef int16 Fq;
 static Fq Fq_freeze(int32 x) {
     x -= q * ((q18 * x) >> 18);
     x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    return (Fq) x;
 }
 
 int PQCLEAN_NTRULPR857_CLEAN_crypto_core_multsntrup857(unsigned char *outbytes, const unsigned char *inbytes, const unsigned char *kbytes) {
@@ -30,9 +30,9 @@ int PQCLEAN_NTRULPR857_CLEAN_crypto_core_multsntrup857(unsigned char *outbytes,
     }
 
     for (i = 0; i < p; ++i) {
-        small gi = kbytes[i];
+        small gi = (small) kbytes[i];
         small gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (small) (gi0 - (gi & (gi0 << 1)));
     }
 
     for (i = 0; i < p; ++i) {
diff --git a/crypto_kem/ntrulpr857/clean/crypto_decode_857x1723.c b/crypto_kem/ntrulpr857/clean/crypto_decode_857x1723.c
index ca5630a2..0720915e 100644
--- a/crypto_kem/ntrulpr857/clean/crypto_decode_857x1723.c
+++ b/crypto_kem/ntrulpr857/clean/crypto_decode_857x1723.c
@@ -30,7 +30,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
 
     *q = 0;
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 2^31 qpart <= xv <= 2^31 qpart + 2^31-1 */
     /* 2^31 qpart m <= xvm <= 2^31 qpart m + (2^31-1)m */
     /* 2^31 qpart m <= 2^31 x <= 2^31 qpart m + (2^31-1)m + x(m-1) */
@@ -42,7 +42,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += qpart;
     /* x <= 49146 */
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 0 <= newx <= (1-1/2^31)m + x(m-1)/2^31 */
     /* 0 <= newx <= m + 49146(2^14-1)/2^31 */
     /* 0 <= newx <= m + 0.4 */
@@ -59,7 +59,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += mask;
     /* x < m */
 
-    *r = x;
+    *r = (uint16) x;
 }
 
 static uint16 uint32_mod_uint14(uint32 x, uint16 m) {
@@ -80,7 +80,7 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_decode_857x1723(void *v, const unsigned cha
     r1 = 0;
     r1 = (r1 << 8) | *--s;
     r1 = uint32_mod_uint14(r1, 160); /* needed only for invalid inputs */
-    R10[0] = r1;
+    R10[0] = (uint16) r1;
 
     r2 = R10[0];
     r2 = (r2 << 8) | *--s;
@@ -88,20 +88,20 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_decode_857x1723(void *v, const unsigned cha
     uint32_divmod_uint14(&r1, &r0, r2, 743);
     R9[0] = r0;
     r1 = uint32_mod_uint14(r1, 14044); /* needed only for invalid inputs */
-    R9[1] = r1;
+    R9[1] = (uint16) r1;
 
     r2 = R9[1];
     r2 = (r2 << 8) | *--s;
     uint32_divmod_uint14(&r1, &r0, r2, 436);
     R8[2] = r0;
     r1 = uint32_mod_uint14(r1, 8246); /* needed only for invalid inputs */
-    R8[3] = r1;
+    R8[3] = (uint16) r1;
     r2 = R9[0];
     r2 = (r2 << 8) | *--s;
     uint32_divmod_uint14(&r1, &r0, r2, 436);
     R8[0] = r0;
     r1 = uint32_mod_uint14(r1, 436); /* needed only for invalid inputs */
-    R8[1] = r1;
+    R8[1] = (uint16) r1;
 
     R7[6] = R8[3];
     for (i = 2; i >= 0; --i) {
@@ -110,7 +110,7 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_decode_857x1723(void *v, const unsigned cha
         uint32_divmod_uint14(&r1, &r0, r2, 334);
         R7[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 334); /* needed only for invalid inputs */
-        R7[2 * i + 1] = r1;
+        R7[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R7[6];
@@ -118,14 +118,14 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_decode_857x1723(void *v, const unsigned cha
     uint32_divmod_uint14(&r1, &r0, r2, 292);
     R6[12] = r0;
     r1 = uint32_mod_uint14(r1, 7229); /* needed only for invalid inputs */
-    R6[13] = r1;
+    R6[13] = (uint16) r1;
     for (i = 5; i >= 0; --i) {
         r2 = R7[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 292);
         R6[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 292); /* needed only for invalid inputs */
-        R6[2 * i + 1] = r1;
+        R6[2 * i + 1] = (uint16) r1;
     }
 
     R5[26] = R6[13];
@@ -135,7 +135,7 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_decode_857x1723(void *v, const unsigned cha
         uint32_divmod_uint14(&r1, &r0, r2, 273);
         R5[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 273); /* needed only for invalid inputs */
-        R5[2 * i + 1] = r1;
+        R5[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R5[26];
@@ -143,7 +143,7 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_decode_857x1723(void *v, const unsigned cha
     uint32_divmod_uint14(&r1, &r0, r2, 4225);
     R4[52] = r0;
     r1 = uint32_mod_uint14(r1, 438); /* needed only for invalid inputs */
-    R4[53] = r1;
+    R4[53] = (uint16) r1;
     for (i = 25; i >= 0; --i) {
         r2 = R5[i];
         r2 = (r2 << 8) | *--s;
@@ -151,7 +151,7 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_decode_857x1723(void *v, const unsigned cha
         uint32_divmod_uint14(&r1, &r0, r2, 4225);
         R4[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 4225); /* needed only for invalid inputs */
-        R4[2 * i + 1] = r1;
+        R4[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R4[53];
@@ -159,13 +159,13 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_decode_857x1723(void *v, const unsigned cha
     uint32_divmod_uint14(&r1, &r0, r2, 65);
     R3[106] = r0;
     r1 = uint32_mod_uint14(r1, 1723); /* needed only for invalid inputs */
-    R3[107] = r1;
+    R3[107] = (uint16) r1;
     for (i = 52; i >= 0; --i) {
         r2 = R4[i];
         uint32_divmod_uint14(&r1, &r0, r2, 65);
         R3[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 65); /* needed only for invalid inputs */
-        R3[2 * i + 1] = r1;
+        R3[2 * i + 1] = (uint16) r1;
     }
 
     R2[214] = R3[107];
@@ -176,7 +176,7 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_decode_857x1723(void *v, const unsigned cha
         uint32_divmod_uint14(&r1, &r0, r2, 2053);
         R2[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 2053); /* needed only for invalid inputs */
-        R2[2 * i + 1] = r1;
+        R2[2 * i + 1] = (uint16) r1;
     }
 
     R1[428] = R2[214];
@@ -187,16 +187,16 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_decode_857x1723(void *v, const unsigned cha
         uint32_divmod_uint14(&r1, &r0, r2, 11597);
         R1[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 11597); /* needed only for invalid inputs */
-        R1[2 * i + 1] = r1;
+        R1[2 * i + 1] = (uint16) r1;
     }
 
-    R0[856] = 3 * R1[428] - 2583;
+    R0[856] = (int16) (3 * R1[428] - 2583);
     for (i = 427; i >= 0; --i) {
         r2 = R1[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 1723);
-        R0[2 * i] = 3 * r0 - 2583;
+        R0[2 * i] = (int16) (3 * r0 - 2583);
         r1 = uint32_mod_uint14(r1, 1723); /* needed only for invalid inputs */
-        R0[2 * i + 1] = 3 * r1 - 2583;
+        R0[2 * i + 1] = (int16) (3 * r1 - 2583);
     }
 }
diff --git a/crypto_kem/ntrulpr857/clean/crypto_decode_857xint16.c b/crypto_kem/ntrulpr857/clean/crypto_decode_857xint16.c
index ec185e8e..d8c620c1 100644
--- a/crypto_kem/ntrulpr857/clean/crypto_decode_857xint16.c
+++ b/crypto_kem/ntrulpr857/clean/crypto_decode_857xint16.c
@@ -8,8 +8,7 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_decode_857xint16(void *v, const unsigned ch
     for (i = 0; i < 857; ++i) {
         uint16_t u0 = s[0];
         uint16_t u1 = s[1];
-        u1 <<= 8;
-        *x = u0 | u1;
+        *x = (uint16_t) (u0 | (u1 << 8));
         x += 1;
         s += 2;
     }
diff --git a/crypto_kem/ntrulpr857/clean/crypto_encode_256x16.c b/crypto_kem/ntrulpr857/clean/crypto_encode_256x16.c
index dcaba21a..81f8c4d2 100644
--- a/crypto_kem/ntrulpr857/clean/crypto_encode_256x16.c
+++ b/crypto_kem/ntrulpr857/clean/crypto_encode_256x16.c
@@ -5,6 +5,6 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_encode_256x16(unsigned char *s, const void
     const unsigned char *T = v;
     int i;
     for (i = 0; i < 128; ++i) {
-        s[i] = T[2 * i] + (T[2 * i + 1] << 4);
+        s[i] = (unsigned char) (T[2 * i] + (T[2 * i + 1] << 4));
     }
 }
diff --git a/crypto_kem/ntrulpr857/clean/crypto_encode_256x2.c b/crypto_kem/ntrulpr857/clean/crypto_encode_256x2.c
index ccd8fb73..8ce08dfe 100644
--- a/crypto_kem/ntrulpr857/clean/crypto_encode_256x2.c
+++ b/crypto_kem/ntrulpr857/clean/crypto_encode_256x2.c
@@ -8,6 +8,6 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_encode_256x2(unsigned char *s, const void *
         s[i] = 0;
     }
     for (i = 0; i < 256; ++i) {
-        s[i >> 3] |= (r[i] & 1) << (i & 7);
+        s[i >> 3] |= (unsigned char) ((r[i] & 1) << (i & 7));
     }
 }
diff --git a/crypto_kem/ntrulpr857/clean/crypto_encode_857x1723.c b/crypto_kem/ntrulpr857/clean/crypto_encode_857x1723.c
index 3922bf8f..0efa1a68 100644
--- a/crypto_kem/ntrulpr857/clean/crypto_encode_857x1723.c
+++ b/crypto_kem/ntrulpr857/clean/crypto_encode_857x1723.c
@@ -15,24 +15,24 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_encode_857x1723(unsigned char *out, const v
     uint32 r2;
 
     for (i = 0; i < 428; ++i) {
-        r0 = (((R0[2 * i] + 2583) & 16383) * 10923) >> 15;
-        r1 = (((R0[2 * i + 1] + 2583) & 16383) * 10923) >> 15;
+        r0 = (uint16) ((((R0[2 * i] + 2583) & 16383) * 10923) >> 15);
+        r1 = (uint16) ((((R0[2 * i + 1] + 2583) & 16383) * 10923) >> 15);
         r2 = r0 + r1 * (uint32)1723;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
-    R[428] = (((R0[856] + 2583) & 16383) * 10923) >> 15;
+    R[428] = (uint16) ((((R0[856] + 2583) & 16383) * 10923) >> 15);
 
     for (i = 0; i < 214; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)11597;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[214] = R[428];
 
@@ -40,11 +40,11 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_encode_857x1723(unsigned char *out, const v
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)2053;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[107] = R[214];
 
@@ -52,39 +52,39 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_encode_857x1723(unsigned char *out, const v
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)65;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[106];
     r1 = R[107];
     r2 = r0 + r1 * (uint32)65;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[53] = r2;
+    R[53] = (uint16) r2;
 
     for (i = 0; i < 26; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)4225;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[52];
     r1 = R[53];
     r2 = r0 + r1 * (uint32)4225;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[26] = r2;
+    R[26] = (uint16) r2;
 
     for (i = 0; i < 13; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)273;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[13] = R[26];
 
@@ -92,18 +92,18 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_encode_857x1723(unsigned char *out, const v
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)292;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 3; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)334;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[3] = R[6];
 
@@ -111,20 +111,20 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_encode_857x1723(unsigned char *out, const v
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)436;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)743;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/ntrulpr857/clean/crypto_encode_857x1723round.c b/crypto_kem/ntrulpr857/clean/crypto_encode_857x1723round.c
index 9e7460ba..229bdc9d 100644
--- a/crypto_kem/ntrulpr857/clean/crypto_encode_857x1723round.c
+++ b/crypto_kem/ntrulpr857/clean/crypto_encode_857x1723round.c
@@ -11,7 +11,7 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_encode_857x1723round(unsigned char *out, co
     int i;
 
     for (i = 0; i < p; ++i) {
-        x[i] = 3 * ((10923 * a[i] + 16384) >> 15);
+        x[i] = (int16) (3 * ((10923 * a[i] + 16384) >> 15));
     }
     PQCLEAN_NTRULPR857_CLEAN_crypto_encode_857x1723(out, x);
 }
diff --git a/crypto_kem/ntrulpr857/clean/crypto_encode_857x3.c b/crypto_kem/ntrulpr857/clean/crypto_encode_857x3.c
index b19644b4..d0646e88 100644
--- a/crypto_kem/ntrulpr857/clean/crypto_encode_857x3.c
+++ b/crypto_kem/ntrulpr857/clean/crypto_encode_857x3.c
@@ -11,9 +11,9 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_encode_857x3(unsigned char *s, const void *
 
     for (i = 0; i < p / 4; ++i) {
         x = *f++ + 1;
-        x += (*f++ + 1) << 2;
-        x += (*f++ + 1) << 4;
-        x += (*f++ + 1) << 6;
+        x += (uint8) ((*f++ + 1) << 2);
+        x += (uint8) ((*f++ + 1) << 4);
+        x += (uint8) ((*f++ + 1) << 6);
         *s++ = x;
     }
     x = *f++ + 1;
diff --git a/crypto_kem/ntrulpr857/clean/crypto_encode_857xint16.c b/crypto_kem/ntrulpr857/clean/crypto_encode_857xint16.c
index 76a54c19..64c559c7 100644
--- a/crypto_kem/ntrulpr857/clean/crypto_encode_857xint16.c
+++ b/crypto_kem/ntrulpr857/clean/crypto_encode_857xint16.c
@@ -7,7 +7,7 @@ void PQCLEAN_NTRULPR857_CLEAN_crypto_encode_857xint16(unsigned char *s, const vo
 
     for (i = 0; i < 857; ++i) {
         uint16_t u = *x++;
-        *s++ = u;
-        *s++ = u >> 8;
+        *s++ = (unsigned char) u;
+        *s++ = (unsigned char) (u >> 8);
     }
 }
diff --git a/crypto_kem/ntrulpr857/clean/kem.c b/crypto_kem/ntrulpr857/clean/kem.c
index 3b7db820..c714d458 100644
--- a/crypto_kem/ntrulpr857/clean/kem.c
+++ b/crypto_kem/ntrulpr857/clean/kem.c
@@ -18,7 +18,7 @@
 
 /* return -1 if x<0; otherwise return 0 */
 static int int16_negative_mask(int16 x) {
-    uint16 u = x;
+    uint16 u = (uint16) x;
     u >>= 15;
     return -(int) u;
     /* alternative with gcc -fwrapv: */
@@ -38,24 +38,24 @@ typedef int16 Fq;
 /* works for -14000000 < x < 14000000 if q in 4591, 4621, 5167 */
 /* assumes twos complement; use, e.g., gcc -fwrapv */
 static Fq Fq_freeze(int32 x) {
-    x -= q * ((q18 * x) >> 18);
-    x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    x -= (int32) (q * ((q18 * x) >> 18));
+    x -= (int32) (q * ((q27 * x + 67108864) >> 27));
+    return (Fq) x;
 }
 
 /* works for all uint32 x */
 static Fq Fq_bigfreeze(uint32 x) {
-    x -= q * ((x * (uint64)q31) >> 31);
-    x -= q * ((x * (uint64)q31) >> 31);
+    x -= (uint32) (q * ((x * (uint64)q31) >> 31));
+    x -= (uint32) (q * ((x * (uint64)q31) >> 31));
     x -= q;
     x += (-(x >> 31)) & (uint32)q;
-    return x;
+    return (Fq) x;
 }
 
 /* ----- Top and Right */
 
 static int8 Top(Fq C) {
-    return (tau1 * (int32)(C + tau0) + 16384) >> 15;
+    return (int8) ((tau1 * (int32)(C + tau0) + 16384) >> 15);
 }
 
 static Fq Right(int8 T) {
@@ -88,7 +88,7 @@ static void Short_fromlist(small *out, const uint32 *in) {
     }
     PQCLEAN_NTRULPR857_CLEAN_crypto_sort_uint32(L, ppadsort);
     for (i = 0; i < p; ++i) {
-        out[i] = (L[i] & 3) - 1;
+        out[i] = (small) ((L[i] & 3) - 1);
     }
 }
 
@@ -99,7 +99,7 @@ static void Short_fromlist(small *out, const uint32 *in) {
 static void Hash(unsigned char *out, const unsigned char *in, int inlen) {
     unsigned char h[64];
     int i;
-    sha512(h, in, inlen);
+    sha512(h, in, (size_t) inlen);
     for (i = 0; i < 32; ++i) {
         out[i] = h[i];
     }
@@ -278,7 +278,7 @@ int PQCLEAN_NTRULPR857_CLEAN_crypto_kem_dec(unsigned char *k, const unsigned cha
             int8 T[I];
             Top_decode(T, c + Rounded_bytes);
             for (i = 0; i < I; ++i) {
-                r[i] = -int16_negative_mask(Fq_freeze(Right(T[i]) - aB[i] + 4 * w + 1));
+                r[i] = (int8) - int16_negative_mask(Fq_freeze(Right(T[i]) - aB[i] + 4 * w + 1));
             }
         }
     }
@@ -289,12 +289,12 @@ int PQCLEAN_NTRULPR857_CLEAN_crypto_kem_dec(unsigned char *k, const unsigned cha
         Hide(cnew, x, r, pk, cache);
         mask = crypto_verify_clen(c, cnew);
         for (i = 0; i < Inputs_bytes; ++i) {
-            x[1 + i] ^= mask & (x[1 + i] ^ rho[i]);
+            x[1 + i] ^= (unsigned char) (mask & (x[1 + i] ^ rho[i]));
         }
         for (i = 0; i < Ciphertexts_bytes + Confirm_bytes; ++i) {
             x[1 + Inputs_bytes + i] = c[i];
         }
-        x[0] = 1 + mask;
+        x[0] = (unsigned char) (1 + mask);
         Hash(k, x, sizeof x);
     }
     return 0;
diff --git a/crypto_kem/sntrup653/avx2/Makefile b/crypto_kem/sntrup653/avx2/Makefile
index bc2fbbd0..ebf71a7b 100644
--- a/crypto_kem/sntrup653/avx2/Makefile
+++ b/crypto_kem/sntrup653/avx2/Makefile
@@ -4,7 +4,7 @@ LIB=libsntrup653_avx2.a
 HEADERS=api.h crypto_core_inv3sntrup653.h crypto_core_invsntrup653.h crypto_core_mult3sntrup653.h crypto_core_multsntrup653.h crypto_core_multsntrup653_ntt.h crypto_core_scale3sntrup653.h crypto_core_weightsntrup653.h crypto_core_wforcesntrup653.h crypto_decode_653x1541.h crypto_decode_653x3.h crypto_decode_653x4621.h crypto_decode_653xint16.h crypto_decode_653xint32.h crypto_decode_int16.h crypto_encode_653x1541.h crypto_encode_653x1541round.h crypto_encode_653x3.h crypto_encode_653x4621.h crypto_encode_653xfreeze3.h crypto_encode_653xint16.h crypto_encode_int16.h crypto_sort_int32.h crypto_sort_uint32.h crypto_stream_aes256ctr.h crypto_verify_897.h params.h 
 OBJECTS=crypto_core_inv3sntrup653.o crypto_core_invsntrup653.o crypto_core_mult3sntrup653.o crypto_core_multsntrup653.o crypto_core_multsntrup653_ntt.o crypto_core_scale3sntrup653.o crypto_core_weightsntrup653.o crypto_core_wforcesntrup653.o crypto_decode_653x1541.o crypto_decode_653x3.o crypto_decode_653x4621.o crypto_decode_653xint16.o crypto_decode_653xint32.o crypto_decode_int16.o crypto_encode_653x1541.o crypto_encode_653x1541round.o crypto_encode_653x3.o crypto_encode_653x4621.o crypto_encode_653xfreeze3.o crypto_encode_653xint16.o crypto_encode_int16.o crypto_sort_int32.o crypto_sort_uint32.o crypto_stream_aes256ctr.o crypto_verify_897.o kem.o 
 
-CFLAGS=-O3 -mavx2 -mbmi2 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -std=c99 -I../../../common $(EXTRAFLAGS)
+CFLAGS=-O3 -mavx2 -mbmi2 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -Wconversion -std=c99 -I../../../common $(EXTRAFLAGS)
 
 all: $(LIB)
 
diff --git a/crypto_kem/sntrup653/avx2/crypto_core_inv3sntrup653.c b/crypto_kem/sntrup653/avx2/crypto_core_inv3sntrup653.c
index 66292c3a..37570727 100644
--- a/crypto_kem/sntrup653/avx2/crypto_core_inv3sntrup653.c
+++ b/crypto_kem/sntrup653/avx2/crypto_core_inv3sntrup653.c
@@ -179,7 +179,7 @@ static void vec256_final(small *out, const vec256 *V0, const vec256 *V1) {
     vec256_tobits(V1, v1);
 
     for (i = 0; i < ppad; ++i) {
-        v[i] = v0[i] + 2 * v1[i] - 4 * (v0[i] & v1[i]);
+        v[i] = (small) (v0[i] + 2 * v1[i] - 4 * (v0[i] & v1[i]));
     }
 
     for (i = 0; i < ppad; ++i) {
@@ -252,11 +252,11 @@ static inline int vec256_bit0mask(vec256 *f) {
 static inline void vec256_divx_1(vec256 *f) {
     vec256 f0 = f[0];
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
 
     low0 = low0 >> 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
 
     f[0] = _mm256_permute4x64_epi64(f0, 0x39);
 }
@@ -265,14 +265,14 @@ static inline void vec256_divx_2(vec256 *f) {
     vec256 f0 = f[0];
     vec256 f1 = f[1];
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
-    unsigned long long low1 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low1 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
 
     low0 = (low0 >> 1) | (low1 << 63);
     low1 = low1 >> 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
-    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, low1), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
+    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, (long long) low1), 0x3);
 
     f[0] = _mm256_permute4x64_epi64(f0, 0x39);
     f[1] = _mm256_permute4x64_epi64(f1, 0x39);
@@ -283,17 +283,17 @@ static inline void vec256_divx_3(vec256 *f) {
     vec256 f1 = f[1];
     vec256 f2 = f[2];
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
-    unsigned long long low1 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
-    unsigned long long low2 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low1 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
+    unsigned long long low2 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
 
     low0 = (low0 >> 1) | (low1 << 63);
     low1 = (low1 >> 1) | (low2 << 63);
     low2 = low2 >> 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
-    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, low1), 0x3);
-    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, low2), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
+    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, (long long) low1), 0x3);
+    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, (long long) low2), 0x3);
 
     f[0] = _mm256_permute4x64_epi64(f0, 0x39);
     f[1] = _mm256_permute4x64_epi64(f1, 0x39);
@@ -303,11 +303,11 @@ static inline void vec256_divx_3(vec256 *f) {
 static inline void vec256_timesx_1(vec256 *f) {
     vec256 f0 = _mm256_permute4x64_epi64(f[0], 0x93);
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
 
     low0 = low0 << 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
 
     f[0] = f0;
 }
@@ -316,14 +316,14 @@ static inline void vec256_timesx_2(vec256 *f) {
     vec256 f0 = _mm256_permute4x64_epi64(f[0], 0x93);
     vec256 f1 = _mm256_permute4x64_epi64(f[1], 0x93);
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
-    unsigned long long low1 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low1 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
 
     low1 = (low1 << 1) | (low0 >> 63);
     low0 = low0 << 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
-    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, low1), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
+    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, (long long) low1), 0x3);
 
     f[0] = f0;
     f[1] = f1;
@@ -336,7 +336,7 @@ static inline void vec256_timesx_3(vec256 *f) {
 
     unsigned long long low0 = *(unsigned long long *) &f0;
     unsigned long long low1 = *(unsigned long long *) &f1;
-    unsigned long long low2 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
+    unsigned long long low2 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
 
     low2 = (low2 << 1) | (low1 >> 63);
     low1 = (low1 << 1) | (low0 >> 63);
@@ -344,7 +344,7 @@ static inline void vec256_timesx_3(vec256 *f) {
 
     *(unsigned long long *) &f0 = low0;
     *(unsigned long long *) &f1 = low1;
-    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, low2), 0x3);
+    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, (long long) low2), 0x3);
 
     f[0] = f0;
     f[1] = f1;
@@ -537,6 +537,6 @@ int PQCLEAN_SNTRUP653_AVX2_crypto_core_inv3sntrup653(unsigned char *outbytes, co
     vec256_scale(V0, V1, c0vec, c1vec);
 
     vec256_final(out, V0, V1);
-    out[p] = negative_mask(minusdelta);
+    out[p] = (small) negative_mask(minusdelta);
     return 0;
 }
diff --git a/crypto_kem/sntrup653/avx2/crypto_core_invsntrup653.c b/crypto_kem/sntrup653/avx2/crypto_core_invsntrup653.c
index e36d64c5..be775232 100644
--- a/crypto_kem/sntrup653/avx2/crypto_core_invsntrup653.c
+++ b/crypto_kem/sntrup653/avx2/crypto_core_invsntrup653.c
@@ -14,11 +14,11 @@
 
 /* return -1 if x!=0; else return 0 */
 static int int16_nonzero_mask(int16 x) {
-    uint16 u = x; /* 0, else 1...65535 */
+    uint16 u = (uint16) x; /* 0, else 1...65535 */
     uint32 v = u; /* 0, else 1...65535 */
     v = -v; /* 0, else 2^32-65535...2^32-1 */
     v >>= 31; /* 0, else 1 */
-    return -v; /* 0, else -1 */
+    return -(int) v; /* 0, else -1 */
 }
 
 /* return -1 if x<0; otherwise return 0 */
@@ -37,7 +37,7 @@ typedef int16 Fq;
 static Fq Fq_freeze(int32 x) {
     x -= q * ((q18 * x) >> 18);
     x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    return (Fq) x;
 }
 
 /* nonnegative e */
@@ -158,13 +158,13 @@ int PQCLEAN_SNTRUP653_AVX2_crypto_core_invsntrup653(unsigned char *outbytes, con
         f0 = f[0];
 
         minusdelta = -delta;
-        swap = int16_negative_mask(minusdelta) & int16_nonzero_mask(g0);
+        swap = int16_negative_mask((int16) minusdelta) & int16_nonzero_mask(g0);
         delta ^= swap & (delta ^ minusdelta);
         delta += 1;
 
         fgflip = swap & (f0 ^ g0);
-        f0 ^= fgflip;
-        g0 ^= fgflip;
+        f0 ^= (Fq) fgflip;
+        g0 ^= (Fq) fgflip;
 
         f[0] = f0;
 
@@ -177,13 +177,13 @@ int PQCLEAN_SNTRUP653_AVX2_crypto_core_invsntrup653(unsigned char *outbytes, con
         f0 = f[0];
 
         minusdelta = -delta;
-        swap = int16_negative_mask(minusdelta) & int16_nonzero_mask(g0);
+        swap = int16_negative_mask((int16) minusdelta) & int16_nonzero_mask(g0);
         delta ^= swap & (delta ^ minusdelta);
         delta += 1;
 
         fgflip = swap & (f0 ^ g0);
-        f0 ^= fgflip;
-        g0 ^= fgflip;
+        f0 ^= (Fq) fgflip;
+        g0 ^= (Fq) fgflip;
 
         f[0] = f0;
 
@@ -197,6 +197,6 @@ int PQCLEAN_SNTRUP653_AVX2_crypto_core_invsntrup653(unsigned char *outbytes, con
     }
 
     crypto_encode_pxint16(outbytes, out);
-    outbytes[2 * p] = int16_nonzero_mask(delta);
+    outbytes[2 * p] = (unsigned char) int16_nonzero_mask((int16) delta);
     return 0;
 }
diff --git a/crypto_kem/sntrup653/avx2/crypto_core_mult3sntrup653.c b/crypto_kem/sntrup653/avx2/crypto_core_mult3sntrup653.c
index 4a692c84..b1b50703 100644
--- a/crypto_kem/sntrup653/avx2/crypto_core_mult3sntrup653.c
+++ b/crypto_kem/sntrup653/avx2/crypto_core_mult3sntrup653.c
@@ -229,14 +229,14 @@ int PQCLEAN_SNTRUP653_AVX2_crypto_core_mult3sntrup653(unsigned char *outbytes, c
     }
 
     for (i = 0; i < p; ++i) {
-        int8 fi = inbytes[i];
+        int8 fi = (int8) inbytes[i];
         int8 fi0 = fi & 1;
-        f[i] = fi0 - (fi & (fi0 << 1));
+        f[i] = (int16) (fi0 - (fi & (fi0 << 1)));
     }
     for (i = 0; i < p; ++i) {
-        int8 gi = kbytes[i];
+        int8 gi = (int8) kbytes[i];
         int8 gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (int16) (gi0 - (gi & (gi0 << 1)));
     }
 
     mult768(fg, f, g);
@@ -252,7 +252,7 @@ int PQCLEAN_SNTRUP653_AVX2_crypto_core_mult3sntrup653(unsigned char *outbytes, c
     }
 
     for (i = 0; i < p; ++i) {
-        outbytes[i] = h[i];
+        outbytes[i] = (unsigned char) h[i];
     }
 
     return 0;
diff --git a/crypto_kem/sntrup653/avx2/crypto_core_multsntrup653.c b/crypto_kem/sntrup653/avx2/crypto_core_multsntrup653.c
index d91f5582..7af7050b 100644
--- a/crypto_kem/sntrup653/avx2/crypto_core_multsntrup653.c
+++ b/crypto_kem/sntrup653/avx2/crypto_core_multsntrup653.c
@@ -291,9 +291,9 @@ int PQCLEAN_SNTRUP653_AVX2_crypto_core_multsntrup653(unsigned char *outbytes, co
         store_x16(&f[i], x);
     }
     for (i = 0; i < p; ++i) {
-        int8 gi = kbytes[i];
+        int8 gi = (int8) kbytes[i];
         int8 gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (int16) (gi0 - (gi & (gi0 << 1)));
     }
 
     mult768(fg, f, g);
diff --git a/crypto_kem/sntrup653/avx2/crypto_core_weightsntrup653.c b/crypto_kem/sntrup653/avx2/crypto_core_weightsntrup653.c
index c2b932e6..b7ef33de 100644
--- a/crypto_kem/sntrup653/avx2/crypto_core_weightsntrup653.c
+++ b/crypto_kem/sntrup653/avx2/crypto_core_weightsntrup653.c
@@ -37,8 +37,8 @@ int PQCLEAN_SNTRUP653_AVX2_crypto_core_weightsntrup653(unsigned char *outbytes,
     sum = _mm256_hadd_epi16(sum, sum);
     /* want sum[0]+sum[8] */
 
-    weight = _mm256_extract_epi16(sum, 0);
-    weight += _mm256_extract_epi16(sum, 8);
+    weight = (int16) _mm256_extract_epi16(sum, 0);
+    weight += (int16) _mm256_extract_epi16(sum, 8);
 
     PQCLEAN_SNTRUP653_AVX2_crypto_encode_int16(outbytes, &weight);
     return 0;
diff --git a/crypto_kem/sntrup653/avx2/crypto_core_wforcesntrup653.c b/crypto_kem/sntrup653/avx2/crypto_core_wforcesntrup653.c
index 90da1ebb..63636176 100644
--- a/crypto_kem/sntrup653/avx2/crypto_core_wforcesntrup653.c
+++ b/crypto_kem/sntrup653/avx2/crypto_core_wforcesntrup653.c
@@ -17,7 +17,7 @@ int PQCLEAN_SNTRUP653_AVX2_crypto_core_wforcesntrup653(unsigned char *out, const
     crypto_core_weight((unsigned char *) &weight, in);
     PQCLEAN_SNTRUP653_AVX2_crypto_decode_int16(&weight, (unsigned char *) &weight);
 
-    mask = (weight - w) | (w - weight);
+    mask = (int16) ((weight - w) | (w - weight));
     mask >>= 15;
     maskvec = _mm256_set1_epi16((short) ~mask);
 
diff --git a/crypto_kem/sntrup653/avx2/crypto_decode_653x1541.c b/crypto_kem/sntrup653/avx2/crypto_decode_653x1541.c
index da5d6f19..493a936e 100644
--- a/crypto_kem/sntrup653/avx2/crypto_decode_653x1541.c
+++ b/crypto_kem/sntrup653/avx2/crypto_decode_653x1541.c
@@ -10,7 +10,7 @@ static inline int16 mullo(int16 x, int16 y) {
 }
 
 static inline int16 mulhi(int16 x, int16 y) {
-    return (x * (int32)y) >> 16;
+    return (int16) ((x * (int32)y) >> 16);
 }
 
 static inline __m256i add(__m256i x, __m256i y) {
@@ -79,7 +79,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
     a0 += s[1 * i + 0]; /* -39...290 */
     a0 = mulhi(a0, 3) - mulhi(mullo(a0, -923), 71); /* -36...35 */
     a0 += (a0 >> 15) & 71; /* 0...70 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, -22153);
 
     /* invalid inputs might need reduction mod 9402 */
@@ -100,7 +100,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
         a0 += s[1 * i + 0]; /* -67...325 */
         a0 = mulhi(a0, 10) - mulhi(mullo(a0, -489), 134); /* -68...67 */
         a0 += (a0 >> 15) & 134; /* 0...133 */
-        a1 = (a2 << 7) + ((s[i] - a0) >> 1);
+        a1 = (int16) ((a2 << 7) + ((s[i] - a0) >> 1));
         a1 = mullo(a1, 19563);
 
         /* invalid inputs might need reduction mod 134 */
@@ -119,7 +119,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
     a0 = mulhi(a0, 1223) - mulhi(mullo(a0, -5681), 2953); /* -1477...1782 */
     a0 += s[1 * i + 0]; /* -1477...2037 */
     a0 += (a0 >> 15) & 2953; /* 0...2952 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, -9543);
 
     /* invalid inputs might need reduction mod 815 */
@@ -136,7 +136,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
         a0 = mulhi(a0, 1223) - mulhi(mullo(a0, -5681), 2953); /* -1505...1514 */
         a0 += s[2 * i + 0]; /* -1505...1769 */
         a0 += (a0 >> 15) & 2953; /* 0...2952 */
-        a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+        a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
         a1 = mullo(a1, -9543);
 
         /* invalid inputs might need reduction mod 2953 */
@@ -158,7 +158,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
         a0 = mulhi(a0, 1756) - mulhi(mullo(a0, -1206), 13910); /* -7142...7159 */
         a0 += s[2 * i + 0]; /* -7142...7414 */
         a0 += (a0 >> 15) & 13910; /* 0...13909 */
-        a1 = (a2 << 15) + (s[2 * i + 1] << 7) + ((s[2 * i] - a0) >> 1);
+        a1 = (int16) ((a2 << 15) + (s[2 * i + 1] << 7) + ((s[2 * i] - a0) >> 1));
         a1 = mullo(a1, -13437);
 
         /* invalid inputs might need reduction mod 13910 */
@@ -178,7 +178,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
         a0 = mulhi(a0, -101) - mulhi(mullo(a0, -8891), 1887); /* -969...943 */
         a0 += s[1 * i + 0]; /* -969...1198 */
         a0 += (a0 >> 15) & 1887; /* 0...1886 */
-        a1 = (a2 << 8) + s[i] - a0;
+        a1 = (int16) ((a2 << 8) + s[i] - a0);
         a1 = mullo(a1, 5279);
 
         /* invalid inputs might need reduction mod 1887 */
@@ -234,7 +234,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
     a0 = mulhi(a0, 2401) - mulhi(mullo(a0, -2487), 6745); /* -3497...3527 */
     a0 += s[2 * i + 0]; /* -3497...3782 */
     a0 += (a0 >> 15) & 6745; /* 0...6744 */
-    a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+    a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
     a1 = mullo(a1, -29207);
 
     /* invalid inputs might need reduction mod 7910 */
@@ -287,7 +287,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
     a0 = mulhi(a0, 64) - mulhi(mullo(a0, -12768), 1314); /* -657...673 */
     a0 += s[1 * i + 0]; /* -657...928 */
     a0 += (a0 >> 15) & 1314; /* 0...1313 */
-    a1 = (a2 << 7) + ((s[i] - a0) >> 1);
+    a1 = (int16) ((a2 << 7) + ((s[i] - a0) >> 1));
     a1 = mullo(a1, -399);
 
     /* invalid inputs might need reduction mod 1541 */
@@ -369,7 +369,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x1541(void *v, const unsigned char
 
     /* R1 ------> R0: reconstruct mod 653*[1541] */
 
-    R0[652] = 3 * R1[326] - 2310;
+    R0[652] = (int16) (3 * R1[326] - 2310);
     s -= 326;
     i = 310;
     for (;;) {
diff --git a/crypto_kem/sntrup653/avx2/crypto_decode_653x4621.c b/crypto_kem/sntrup653/avx2/crypto_decode_653x4621.c
index 04368a95..91468ec6 100644
--- a/crypto_kem/sntrup653/avx2/crypto_decode_653x4621.c
+++ b/crypto_kem/sntrup653/avx2/crypto_decode_653x4621.c
@@ -10,7 +10,7 @@ static inline int16 mullo(int16 x, int16 y) {
 }
 
 static inline int16 mulhi(int16 x, int16 y) {
-    return (x * (int32)y) >> 16;
+    return (int16) ((x * (int32)y) >> 16);
 }
 
 static inline __m256i add(__m256i x, __m256i y) {
@@ -81,7 +81,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x4621(void *v, const unsigned char
     a0 = mulhi(a0, 396) - mulhi(mullo(a0, -20092), 835); /* -421...422 */
     a0 += s[2 * i + 0]; /* -421...677 */
     a0 += (a0 >> 15) & 835; /* 0...834 */
-    a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+    a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
     a1 = mullo(a1, 8555);
 
     /* invalid inputs might need reduction mod 6708 */
@@ -103,7 +103,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x4621(void *v, const unsigned char
         a0 = mulhi(a0, 3088) - mulhi(mullo(a0, -2268), 7396); /* -3873...3920 */
         a0 += s[2 * i + 0]; /* -3873...4175 */
         a0 += (a0 >> 15) & 7396; /* 0...7395 */
-        a1 = (a2 << 14) + (s[2 * i + 1] << 6) + ((s[2 * i] - a0) >> 2);
+        a1 = (int16) ((a2 << 14) + (s[2 * i + 1] << 6) + ((s[2 * i] - a0) >> 2));
         a1 = mullo(a1, -18679);
 
         /* invalid inputs might need reduction mod 7396 */
@@ -120,7 +120,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x4621(void *v, const unsigned char
     a2 = a0 = R8[2];
     a0 = mulhi(a0, 4) - mulhi(mullo(a0, -762), 86); /* -43...44 */
     a0 += (a0 >> 15) & 86; /* 0...85 */
-    a1 = (a2 - a0) >> 1;
+    a1 = (int16) ((a2 - a0) >> 1);
     a1 = mullo(a1, -16765);
 
     /* invalid inputs might need reduction mod 78 */
@@ -134,7 +134,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x4621(void *v, const unsigned char
         a2 = a0 = R8[i];
         a0 = mulhi(a0, 4) - mulhi(mullo(a0, -762), 86); /* -43...44 */
         a0 += (a0 >> 15) & 86; /* 0...85 */
-        a1 = (a2 - a0) >> 1;
+        a1 = (int16) ((a2 - a0) >> 1);
         a1 = mullo(a1, -16765);
 
         /* invalid inputs might need reduction mod 86 */
@@ -156,7 +156,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x4621(void *v, const unsigned char
         a0 = mulhi(a0, -14) - mulhi(mullo(a0, -7079), 2370); /* -1186...1185 */
         a0 += s[2 * i + 0]; /* -1186...1440 */
         a0 += (a0 >> 15) & 2370; /* 0...2369 */
-        a1 = (a2 << 15) + (s[2 * i + 1] << 7) + ((s[2 * i] - a0) >> 1);
+        a1 = (int16) ((a2 << 15) + (s[2 * i + 1] << 7) + ((s[2 * i] - a0) >> 1));
         a1 = mullo(a1, -8351);
 
         /* invalid inputs might need reduction mod 2370 */
@@ -178,7 +178,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x4621(void *v, const unsigned char
         a0 = mulhi(a0, 4710) - mulhi(mullo(a0, -1346), 12461); /* -6679...6781 */
         a0 += s[2 * i + 0]; /* -6679...7036 */
         a0 += (a0 >> 15) & 12461; /* 0...12460 */
-        a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+        a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
         a1 = mullo(a1, -19675);
 
         /* invalid inputs might need reduction mod 12461 */
@@ -234,7 +234,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x4621(void *v, const unsigned char
     a0 = mulhi(a0, 248) - mulhi(mullo(a0, -24818), 676); /* -340...340 */
     a0 += s[2 * i + 0]; /* -340...595 */
     a0 += (a0 >> 15) & 676; /* 0...675 */
-    a1 = (a2 << 14) + (s[2 * i + 1] << 6) + ((s[2 * i] - a0) >> 2);
+    a1 = (int16) ((a2 << 14) + (s[2 * i + 1] << 6) + ((s[2 * i] - a0) >> 2));
     a1 = mullo(a1, -23655);
 
     /* invalid inputs might need reduction mod 7510 */
@@ -285,7 +285,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653x4621(void *v, const unsigned char
     a0 -= 416; /* -640..>47 */
     a0 += (a0 >> 15) & 416; /* -224...415 */
     a0 += (a0 >> 15) & 416; /* 0...415 */
-    a1 = (a2 << 3) + ((s[i] - a0) >> 5);
+    a1 = (int16) ((a2 << 3) + ((s[i] - a0) >> 5));
     a1 = mullo(a1, 20165);
 
     /* invalid inputs might need reduction mod 4621 */
diff --git a/crypto_kem/sntrup653/avx2/crypto_decode_653xint16.c b/crypto_kem/sntrup653/avx2/crypto_decode_653xint16.c
index dfa1cda2..d297f24c 100644
--- a/crypto_kem/sntrup653/avx2/crypto_decode_653xint16.c
+++ b/crypto_kem/sntrup653/avx2/crypto_decode_653xint16.c
@@ -8,8 +8,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_decode_653xint16(void *v, const unsigned char
     for (i = 0; i < 653; ++i) {
         uint16_t u0 = s[0];
         uint16_t u1 = s[1];
-        u1 <<= 8;
-        *x = u0 | u1;
+        *x = (uint16_t) (u0 | (u1 << 8));
         x += 1;
         s += 2;
     }
diff --git a/crypto_kem/sntrup653/avx2/crypto_decode_int16.c b/crypto_kem/sntrup653/avx2/crypto_decode_int16.c
index 7db93101..b798013c 100644
--- a/crypto_kem/sntrup653/avx2/crypto_decode_int16.c
+++ b/crypto_kem/sntrup653/avx2/crypto_decode_int16.c
@@ -4,6 +4,6 @@
 void PQCLEAN_SNTRUP653_AVX2_crypto_decode_int16(void *x, const unsigned char *s) {
     uint16_t u0 = s[0];
     uint16_t u1 = s[1];
-    u1 <<= 8;
+    u1 = (uint16_t) (u1 << 8);
     *(uint16_t *) x = u0 | u1;
 }
diff --git a/crypto_kem/sntrup653/avx2/crypto_encode_653x1541.c b/crypto_kem/sntrup653/avx2/crypto_encode_653x1541.c
index 4269c16b..36cbb7ee 100644
--- a/crypto_kem/sntrup653/avx2/crypto_encode_653x1541.c
+++ b/crypto_kem/sntrup653/avx2/crypto_encode_653x1541.c
@@ -42,26 +42,26 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x1541(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
-    R[326] = (((R0[652] + 2310) & 16383) * 10923) >> 15;
+    R[326] = (uint16) ((((R0[652] + 2310) & 16383) * 10923) >> 15);
 
     reading = (uint16 *) R;
     writing = R;
@@ -124,22 +124,22 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x1541(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -204,22 +204,22 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x1541(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -229,9 +229,9 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x1541(unsigned char *out, const voi
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1887;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[10] = R[20];
 
@@ -239,11 +239,11 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x1541(unsigned char *out, const voi
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)13910;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[5] = R[10];
 
@@ -251,36 +251,36 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x1541(unsigned char *out, const voi
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)2953;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[4];
     r1 = R[5];
     r2 = r0 + r1 * (uint32)2953;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[2] = r2;
+    R[2] = (uint16) r2;
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)134;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)71;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/sntrup653/avx2/crypto_encode_653x1541round.c b/crypto_kem/sntrup653/avx2/crypto_encode_653x1541round.c
index d019eeb5..b2e34128 100644
--- a/crypto_kem/sntrup653/avx2/crypto_encode_653x1541round.c
+++ b/crypto_kem/sntrup653/avx2/crypto_encode_653x1541round.c
@@ -44,26 +44,26 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x1541round(unsigned char *out, cons
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
-    R[326] = (((3 * ((10923 * R0[652] + 16384) >> 15) + 2310) & 16383) * 10923) >> 15;
+    R[326] = (uint16) ((((3 * ((10923 * R0[652] + 16384) >> 15) + 2310) & 16383) * 10923) >> 15);
 
     reading = (uint16 *) R;
     writing = R;
@@ -126,22 +126,22 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x1541round(unsigned char *out, cons
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -206,22 +206,22 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x1541round(unsigned char *out, cons
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -231,9 +231,9 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x1541round(unsigned char *out, cons
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1887;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[10] = R[20];
 
@@ -241,11 +241,11 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x1541round(unsigned char *out, cons
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)13910;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[5] = R[10];
 
@@ -253,36 +253,36 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x1541round(unsigned char *out, cons
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)2953;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[4];
     r1 = R[5];
     r2 = r0 + r1 * (uint32)2953;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[2] = r2;
+    R[2] = (uint16) r2;
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)134;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)71;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/sntrup653/avx2/crypto_encode_653x4621.c b/crypto_kem/sntrup653/avx2/crypto_encode_653x4621.c
index 45c443b7..530a9ce3 100644
--- a/crypto_kem/sntrup653/avx2/crypto_encode_653x4621.c
+++ b/crypto_kem/sntrup653/avx2/crypto_encode_653x4621.c
@@ -82,22 +82,22 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x4621(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -125,22 +125,22 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x4621(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -162,33 +162,33 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x4621(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
     r0 = R[80];
     r1 = R[81];
     r2 = r0 + r1 * (uint32)676;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[40] = r2;
+    R[40] = (uint16) r2;
 
     reading = (uint16 *) R;
     writing = R;
@@ -212,22 +212,22 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x4621(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -237,11 +237,11 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x4621(unsigned char *out, const voi
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)12461;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[10] = R[20];
 
@@ -249,11 +249,11 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x4621(unsigned char *out, const voi
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)2370;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[5] = R[10];
 
@@ -261,28 +261,28 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653x4621(unsigned char *out, const voi
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)86;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)7396;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)835;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/sntrup653/avx2/crypto_encode_653xint16.c b/crypto_kem/sntrup653/avx2/crypto_encode_653xint16.c
index 5443662e..28c79250 100644
--- a/crypto_kem/sntrup653/avx2/crypto_encode_653xint16.c
+++ b/crypto_kem/sntrup653/avx2/crypto_encode_653xint16.c
@@ -7,7 +7,7 @@ void PQCLEAN_SNTRUP653_AVX2_crypto_encode_653xint16(unsigned char *s, const void
 
     for (i = 0; i < 653; ++i) {
         uint16_t u = *x++;
-        *s++ = u;
-        *s++ = u >> 8;
+        *s++ = (unsigned char) u;
+        *s++ = (unsigned char) (u >> 8);
     }
 }
diff --git a/crypto_kem/sntrup653/avx2/crypto_encode_int16.c b/crypto_kem/sntrup653/avx2/crypto_encode_int16.c
index aa327402..b69b49dd 100644
--- a/crypto_kem/sntrup653/avx2/crypto_encode_int16.c
+++ b/crypto_kem/sntrup653/avx2/crypto_encode_int16.c
@@ -4,6 +4,6 @@
 
 void PQCLEAN_SNTRUP653_AVX2_crypto_encode_int16(unsigned char *s, const void *x) {
     uint16 u = *(const uint16 *) x;
-    s[0] = u;
-    s[1] = u >> 8;
+    s[0] = (unsigned char) u;
+    s[1] = (unsigned char) (u >> 8);
 }
diff --git a/crypto_kem/sntrup653/avx2/crypto_sort_int32.c b/crypto_kem/sntrup653/avx2/crypto_sort_int32.c
index 1db58519..77d117c6 100644
--- a/crypto_kem/sntrup653/avx2/crypto_sort_int32.c
+++ b/crypto_kem/sntrup653/avx2/crypto_sort_int32.c
@@ -44,7 +44,7 @@ static void minmax_vector(int32 *x, int32 *y, size_t n) {
         int32x8_MINMAX(x0, y0);
         int32x8_store(x + n - 8, x0);
         int32x8_store(y + n - 8, y0);
-        n &= ~7;
+        n &= ~(size_t) 7;
     }
     do {
         int32x8 x0 = int32x8_load(x);
diff --git a/crypto_kem/sntrup653/avx2/crypto_verify_897.c b/crypto_kem/sntrup653/avx2/crypto_verify_897.c
index 4b298e67..10cffa5b 100644
--- a/crypto_kem/sntrup653/avx2/crypto_verify_897.c
+++ b/crypto_kem/sntrup653/avx2/crypto_verify_897.c
@@ -27,10 +27,10 @@ int PQCLEAN_SNTRUP653_AVX2_crypto_verify_897(const unsigned char *x, const unsig
     diff |= _mm256_srli_epi32(diff, 16);
     diff |= _mm256_srli_epi64(diff, 32);
 
-    differentbits = _mm256_extract_epi8(diff, 0);
-    differentbits |= _mm256_extract_epi8(diff, 8);
-    differentbits |= _mm256_extract_epi8(diff, 16);
-    differentbits |= _mm256_extract_epi8(diff, 24);
+    differentbits = (unsigned int) _mm256_extract_epi8(diff, 0);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 8);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 16);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 24);
 
     return (int) (1 & ((differentbits - 1) >> 8)) - 1;
 }
diff --git a/crypto_kem/sntrup653/avx2/kem.c b/crypto_kem/sntrup653/avx2/kem.c
index 6c53b32e..12c67d51 100644
--- a/crypto_kem/sntrup653/avx2/kem.c
+++ b/crypto_kem/sntrup653/avx2/kem.c
@@ -65,7 +65,7 @@ static void Rq_recip3(Fq *out, const small *in) {
 static void Hash(unsigned char *out, const unsigned char *in, int inlen) {
     unsigned char h[64];
     int i;
-    sha512(h, in, inlen);
+    sha512(h, in, (size_t) inlen);
     for (i = 0; i < 32; ++i) {
         out[i] = h[i];
     }
@@ -103,7 +103,7 @@ static void Short_random(small *out) {
     }
     PQCLEAN_SNTRUP653_AVX2_crypto_sort_uint32(L, ppadsort);
     for (i = 0; i < p; ++i) {
-        out[i] = (L[i] & 3) - 1;
+        out[i] = (small) ((L[i] & 3) - 1);
     }
 }
 
@@ -115,7 +115,7 @@ static void Small_random(small *out) {
         L[i] = urandom32();
     }
     for (i = 0; i < p; ++i) {
-        out[i] = (((L[i] & 0x3fffffff) * 3) >> 30) - 1;
+        out[i] = (small) ((((L[i] & 0x3fffffff) * 3) >> 30) - 1);
     }
 }
 
@@ -248,13 +248,13 @@ int PQCLEAN_SNTRUP653_AVX2_crypto_kem_dec(unsigned char *k, const unsigned char
         Hide(x, cnew, r_enc, r, pk, cache);
         mask = crypto_verify_clen(c, cnew);
         for (i = 0; i < Small_bytes; ++i) {
-            r_enc[i + 1] ^= mask & (r_enc[i + 1] ^ rho[i]);
+            r_enc[i + 1] ^= (unsigned char) (mask & (r_enc[i + 1] ^ rho[i]));
         }
         Hash(x + 1, r_enc, 1 + Small_bytes); /* XXX: can instead do cmov on cached hash of rho */
         for (i = 0; i < Ciphertexts_bytes + Confirm_bytes; ++i) {
             x[1 + Hash_bytes + i] = c[i];
         }
-        x[0] = 1 + mask;
+        x[0] = (unsigned char) (1 + mask);
         Hash(k, x, sizeof x);
     }
     return 0;
diff --git a/crypto_kem/sntrup653/clean/Makefile b/crypto_kem/sntrup653/clean/Makefile
index 81ded6d1..b454b3cb 100644
--- a/crypto_kem/sntrup653/clean/Makefile
+++ b/crypto_kem/sntrup653/clean/Makefile
@@ -4,7 +4,7 @@ LIB=libsntrup653_clean.a
 HEADERS=api.h crypto_core_inv3sntrup653.h crypto_core_invsntrup653.h crypto_core_mult3sntrup653.h crypto_core_multsntrup653.h crypto_core_scale3sntrup653.h crypto_core_weightsntrup653.h crypto_core_wforcesntrup653.h crypto_decode_653x1541.h crypto_decode_653x3.h crypto_decode_653x4621.h crypto_decode_653xint16.h crypto_decode_653xint32.h crypto_encode_653x1541.h crypto_encode_653x1541round.h crypto_encode_653x3.h crypto_encode_653x4621.h crypto_encode_653xfreeze3.h crypto_encode_653xint16.h crypto_encode_int16.h crypto_sort_int32.h crypto_sort_uint32.h crypto_stream_aes256ctr.h crypto_verify_897.h params.h 
 OBJECTS=crypto_core_inv3sntrup653.o crypto_core_invsntrup653.o crypto_core_mult3sntrup653.o crypto_core_multsntrup653.o crypto_core_scale3sntrup653.o crypto_core_weightsntrup653.o crypto_core_wforcesntrup653.o crypto_decode_653x1541.o crypto_decode_653x3.o crypto_decode_653x4621.o crypto_decode_653xint16.o crypto_decode_653xint32.o crypto_encode_653x1541.o crypto_encode_653x1541round.o crypto_encode_653x3.o crypto_encode_653x4621.o crypto_encode_653xfreeze3.o crypto_encode_653xint16.o crypto_encode_int16.o crypto_sort_int32.o crypto_sort_uint32.o crypto_stream_aes256ctr.o crypto_verify_897.o kem.o 
 
-CFLAGS=-O3 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -std=c99 -I../../../common $(EXTRAFLAGS)
+CFLAGS=-O3 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -Wconversion -std=c99 -I../../../common $(EXTRAFLAGS)
 
 all: $(LIB)
 
diff --git a/crypto_kem/sntrup653/clean/crypto_core_inv3sntrup653.c b/crypto_kem/sntrup653/clean/crypto_core_inv3sntrup653.c
index 27a30edc..bb4e752c 100644
--- a/crypto_kem/sntrup653/clean/crypto_core_inv3sntrup653.c
+++ b/crypto_kem/sntrup653/clean/crypto_core_inv3sntrup653.c
@@ -13,16 +13,16 @@
 
 /* return -1 if x!=0; else return 0 */
 static int int16_nonzero_mask(int16 x) {
-    uint16 u = x; /* 0, else 1...65535 */
+    uint16 u = (uint16) x; /* 0, else 1...65535 */
     uint32 v = u; /* 0, else 1...65535 */
     v = -v; /* 0, else 2^32-65535...2^32-1 */
     v >>= 31; /* 0, else 1 */
-    return -v; /* 0, else -1 */
+    return -(int) v; /* 0, else -1 */
 }
 
 /* return -1 if x<0; otherwise return 0 */
 static int int16_negative_mask(int16 x) {
-    uint16 u = x;
+    uint16 u = (uint16) x;
     u >>= 15;
     return -(int) u;
     /* alternative with gcc -fwrapv: */
@@ -36,7 +36,7 @@ typedef int8 small;
 
 /* works for -16384 <= x < 16384 */
 static small F3_freeze(int16 x) {
-    return x - 3 * ((10923 * x + 16384) >> 15);
+    return (small) (x - 3 * ((10923 * x + 16384) >> 15));
 }
 
 /* byte p of output is 0 if recip succeeded; else -1 */
@@ -61,7 +61,7 @@ int PQCLEAN_SNTRUP653_CLEAN_crypto_core_inv3sntrup653(unsigned char *outbytes, c
     f[p - 1] = f[p] = -1;
     for (i = 0; i < p; ++i) {
         small i1 = in[i] & 1;
-        g[p - 1 - i] = i1 - (in[i] & (i1 << 1));
+        g[p - 1 - i] = (small) (i1 - (in[i] & (i1 << 1)));
     }
     g[p] = 0;
 
@@ -74,24 +74,24 @@ int PQCLEAN_SNTRUP653_CLEAN_crypto_core_inv3sntrup653(unsigned char *outbytes, c
         v[0] = 0;
 
         sign = -g[0] * f[0];
-        swap = int16_negative_mask(-delta) & int16_nonzero_mask(g[0]);
+        swap = int16_negative_mask(-(int16) delta) & int16_nonzero_mask(g[0]);
         delta ^= swap & (delta ^ -delta);
         delta += 1;
 
         for (i = 0; i < p + 1; ++i) {
             t = swap & (f[i] ^ g[i]);
-            f[i] ^= t;
-            g[i] ^= t;
+            f[i] ^= (small) t;
+            g[i] ^= (small) t;
             t = swap & (v[i] ^ r[i]);
-            v[i] ^= t;
-            r[i] ^= t;
+            v[i] ^= (small) t;
+            r[i] ^= (small) t;
         }
 
         for (i = 0; i < p + 1; ++i) {
-            g[i] = F3_freeze(g[i] + sign * f[i]);
+            g[i] = F3_freeze((int16) (g[i] + sign * f[i]));
         }
         for (i = 0; i < p + 1; ++i) {
-            r[i] = F3_freeze(r[i] + sign * v[i]);
+            r[i] = F3_freeze((int16) (r[i] + sign * v[i]));
         }
 
         for (i = 0; i < p; ++i) {
@@ -102,9 +102,9 @@ int PQCLEAN_SNTRUP653_CLEAN_crypto_core_inv3sntrup653(unsigned char *outbytes, c
 
     sign = f[0];
     for (i = 0; i < p; ++i) {
-        out[i] = sign * v[p - 1 - i];
+        out[i] = (small) sign * v[p - 1 - i];
     }
 
-    out[p] = int16_nonzero_mask(delta);
+    out[p] = (small) int16_nonzero_mask((int16) delta);
     return 0;
 }
diff --git a/crypto_kem/sntrup653/clean/crypto_core_invsntrup653.c b/crypto_kem/sntrup653/clean/crypto_core_invsntrup653.c
index e69c7c40..572abb39 100644
--- a/crypto_kem/sntrup653/clean/crypto_core_invsntrup653.c
+++ b/crypto_kem/sntrup653/clean/crypto_core_invsntrup653.c
@@ -13,16 +13,16 @@
 
 /* return -1 if x!=0; else return 0 */
 static int int16_nonzero_mask(int16 x) {
-    uint16 u = x; /* 0, else 1...65535 */
+    uint16 u = (uint16) x; /* 0, else 1...65535 */
     uint32 v = u; /* 0, else 1...65535 */
     v = -v; /* 0, else 2^32-65535...2^32-1 */
     v >>= 31; /* 0, else 1 */
-    return -v; /* 0, else -1 */
+    return -(int) v; /* 0, else -1 */
 }
 
 /* return -1 if x<0; otherwise return 0 */
 static int int16_negative_mask(int16 x) {
-    uint16 u = x;
+    uint16 u = (uint16) x;
     u >>= 15;
     return -(int) u;
     /* alternative with gcc -fwrapv: */
@@ -40,7 +40,7 @@ typedef int16 Fq;
 static Fq Fq_freeze(int32 x) {
     x -= q * ((q18 * x) >> 18);
     x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    return (Fq) x;
 }
 
 static Fq Fq_recip(Fq a1) {
@@ -91,17 +91,17 @@ int PQCLEAN_SNTRUP653_CLEAN_crypto_core_invsntrup653(unsigned char *outbytes, co
         }
         v[0] = 0;
 
-        swap = int16_negative_mask(-delta) & int16_nonzero_mask(g[0]);
+        swap = int16_negative_mask((int16) - delta) & int16_nonzero_mask(g[0]);
         delta ^= swap & (delta ^ -delta);
         delta += 1;
 
         for (i = 0; i < p + 1; ++i) {
             t = swap & (f[i] ^ g[i]);
-            f[i] ^= t;
-            g[i] ^= t;
+            f[i] ^= (Fq) t;
+            g[i] ^= (Fq) t;
             t = swap & (v[i] ^ r[i]);
-            v[i] ^= t;
-            r[i] ^= t;
+            v[i] ^= (Fq) t;
+            r[i] ^= (Fq) t;
         }
 
         f0 = f[0];
@@ -125,7 +125,6 @@ int PQCLEAN_SNTRUP653_CLEAN_crypto_core_invsntrup653(unsigned char *outbytes, co
     }
 
     crypto_encode_pxint16(outbytes, out);
-
-    outbytes[2 * p] = int16_nonzero_mask(delta);
+    outbytes[2 * p] = (unsigned char) int16_nonzero_mask((int16) delta);
     return 0;
 }
diff --git a/crypto_kem/sntrup653/clean/crypto_core_mult3sntrup653.c b/crypto_kem/sntrup653/clean/crypto_core_mult3sntrup653.c
index 3947b9df..7d0d4636 100644
--- a/crypto_kem/sntrup653/clean/crypto_core_mult3sntrup653.c
+++ b/crypto_kem/sntrup653/clean/crypto_core_mult3sntrup653.c
@@ -8,7 +8,7 @@ typedef int8 small;
 
 /* works for -16384 <= x < 16384 */
 static small F3_freeze(int16 x) {
-    return x - 3 * ((10923 * x + 16384) >> 15);
+    return (small) (x - 3 * ((10923 * x + 16384) >> 15));
 }
 
 int PQCLEAN_SNTRUP653_CLEAN_crypto_core_mult3sntrup653(unsigned char *outbytes, const unsigned char *inbytes, const unsigned char *kbytes) {
@@ -20,27 +20,27 @@ int PQCLEAN_SNTRUP653_CLEAN_crypto_core_mult3sntrup653(unsigned char *outbytes,
     int i, j;
 
     for (i = 0; i < p; ++i) {
-        small fi = inbytes[i];
+        small fi = (small) inbytes[i];
         small fi0 = fi & 1;
-        f[i] = fi0 - (fi & (fi0 << 1));
+        f[i] = (small) (fi0 - (fi & (fi0 << 1)));
     }
     for (i = 0; i < p; ++i) {
-        small gi = kbytes[i];
+        small gi = (small) kbytes[i];
         small gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (small) (gi0 - (gi & (gi0 << 1)));
     }
 
     for (i = 0; i < p; ++i) {
         result = 0;
         for (j = 0; j <= i; ++j) {
-            result += f[j] * g[i - j];
+            result += (small) (f[j] * g[i - j]);
         }
         fg[i] = F3_freeze(result);
     }
     for (i = p; i < p + p - 1; ++i) {
         result = 0;
         for (j = i - p + 1; j < p; ++j) {
-            result += f[j] * g[i - j];
+            result += (small) (f[j] * g[i - j]);
         }
         fg[i] = F3_freeze(result);
     }
diff --git a/crypto_kem/sntrup653/clean/crypto_core_multsntrup653.c b/crypto_kem/sntrup653/clean/crypto_core_multsntrup653.c
index 5b0e6c98..d44aedae 100644
--- a/crypto_kem/sntrup653/clean/crypto_core_multsntrup653.c
+++ b/crypto_kem/sntrup653/clean/crypto_core_multsntrup653.c
@@ -14,7 +14,7 @@ typedef int16 Fq;
 static Fq Fq_freeze(int32 x) {
     x -= q * ((q18 * x) >> 18);
     x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    return (Fq) x;
 }
 
 int PQCLEAN_SNTRUP653_CLEAN_crypto_core_multsntrup653(unsigned char *outbytes, const unsigned char *inbytes, const unsigned char *kbytes) {
@@ -30,9 +30,9 @@ int PQCLEAN_SNTRUP653_CLEAN_crypto_core_multsntrup653(unsigned char *outbytes, c
     }
 
     for (i = 0; i < p; ++i) {
-        small gi = kbytes[i];
+        small gi = (small) kbytes[i];
         small gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (small) (gi0 - (gi & (gi0 << 1)));
     }
 
     for (i = 0; i < p; ++i) {
diff --git a/crypto_kem/sntrup653/clean/crypto_core_wforcesntrup653.c b/crypto_kem/sntrup653/clean/crypto_core_wforcesntrup653.c
index f8a64711..80e55851 100644
--- a/crypto_kem/sntrup653/clean/crypto_core_wforcesntrup653.c
+++ b/crypto_kem/sntrup653/clean/crypto_core_wforcesntrup653.c
@@ -12,11 +12,11 @@ typedef int8 small;
 
 /* return -1 if x!=0; else return 0 */
 static int int16_nonzero_mask(int16 x) {
-    uint16 u = x; /* 0, else 1...65535 */
+    uint16 u = (uint16) x; /* 0, else 1...65535 */
     uint32 v = u; /* 0, else 1...65535 */
     v = -v; /* 0, else 2^32-65535...2^32-1 */
     v >>= 31; /* 0, else 1 */
-    return -v; /* 0, else -1 */
+    return -(int) v; /* 0, else -1 */
 }
 
 /* 0 if Weightw_is(r), else -1 */
@@ -27,7 +27,7 @@ static int Weightw_mask(const small *r) {
     for (i = 0; i < p; ++i) {
         weight += r[i] & 1;
     }
-    return int16_nonzero_mask(weight - w);
+    return int16_nonzero_mask((int16) (weight - w));
 }
 
 /* out = in if bottom bits of in have weight w */
@@ -39,10 +39,10 @@ int PQCLEAN_SNTRUP653_CLEAN_crypto_core_wforcesntrup653(unsigned char *outbytes,
 
     mask = Weightw_mask(in); /* 0 if weight w, else -1 */
     for (i = 0; i < w; ++i) {
-        out[i] = ((in[i] ^ 1) & ~mask) ^ 1;
+        out[i] = (small) (((in[i] ^ 1) & ~mask) ^ 1);
     }
     for (i = w; i < p; ++i) {
-        out[i] = in[i] & ~mask;
+        out[i] = (small) (in[i] & ~mask);
     }
     return 0;
 }
diff --git a/crypto_kem/sntrup653/clean/crypto_decode_653x1541.c b/crypto_kem/sntrup653/clean/crypto_decode_653x1541.c
index b6a10aca..acaf947a 100644
--- a/crypto_kem/sntrup653/clean/crypto_decode_653x1541.c
+++ b/crypto_kem/sntrup653/clean/crypto_decode_653x1541.c
@@ -30,7 +30,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
 
     *q = 0;
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 2^31 qpart <= xv <= 2^31 qpart + 2^31-1 */
     /* 2^31 qpart m <= xvm <= 2^31 qpart m + (2^31-1)m */
     /* 2^31 qpart m <= 2^31 x <= 2^31 qpart m + (2^31-1)m + x(m-1) */
@@ -42,7 +42,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += qpart;
     /* x <= 49146 */
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 0 <= newx <= (1-1/2^31)m + x(m-1)/2^31 */
     /* 0 <= newx <= m + 49146(2^14-1)/2^31 */
     /* 0 <= newx <= m + 0.4 */
@@ -59,7 +59,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += mask;
     /* x < m */
 
-    *r = x;
+    *r = (uint16) x;
 }
 
 static uint16 uint32_mod_uint14(uint32 x, uint16 m) {
@@ -81,14 +81,14 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x1541(void *v, const unsigned char
     r1 = (r1 << 8) | *--s;
     r1 = (r1 << 8) | *--s;
     r1 = uint32_mod_uint14(r1, 2608); /* needed only for invalid inputs */
-    R10[0] = r1;
+    R10[0] = (uint16) r1;
 
     r2 = R10[0];
     r2 = (r2 << 8) | *--s;
     uint32_divmod_uint14(&r1, &r0, r2, 71);
     R9[0] = r0;
     r1 = uint32_mod_uint14(r1, 9402); /* needed only for invalid inputs */
-    R9[1] = r1;
+    R9[1] = (uint16) r1;
 
     R8[2] = R9[1];
     r2 = R9[0];
@@ -96,14 +96,14 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x1541(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 134);
     R8[0] = r0;
     r1 = uint32_mod_uint14(r1, 134); /* needed only for invalid inputs */
-    R8[1] = r1;
+    R8[1] = (uint16) r1;
 
     r2 = R8[2];
     r2 = (r2 << 8) | *--s;
     uint32_divmod_uint14(&r1, &r0, r2, 2953);
     R7[4] = r0;
     r1 = uint32_mod_uint14(r1, 815); /* needed only for invalid inputs */
-    R7[5] = r1;
+    R7[5] = (uint16) r1;
     for (i = 1; i >= 0; --i) {
         r2 = R8[i];
         r2 = (r2 << 8) | *--s;
@@ -111,7 +111,7 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x1541(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 2953);
         R7[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 2953); /* needed only for invalid inputs */
-        R7[2 * i + 1] = r1;
+        R7[2 * i + 1] = (uint16) r1;
     }
 
     R6[10] = R7[5];
@@ -122,7 +122,7 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x1541(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 13910);
         R6[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 13910); /* needed only for invalid inputs */
-        R6[2 * i + 1] = r1;
+        R6[2 * i + 1] = (uint16) r1;
     }
 
     R5[20] = R6[10];
@@ -132,7 +132,7 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x1541(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 1887);
         R5[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 1887); /* needed only for invalid inputs */
-        R5[2 * i + 1] = r1;
+        R5[2 * i + 1] = (uint16) r1;
     }
 
     R4[40] = R5[20];
@@ -142,7 +142,7 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x1541(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 695);
         R4[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 695); /* needed only for invalid inputs */
-        R4[2 * i + 1] = r1;
+        R4[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R4[40];
@@ -151,7 +151,7 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x1541(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 6745);
     R3[80] = r0;
     r1 = uint32_mod_uint14(r1, 7910); /* needed only for invalid inputs */
-    R3[81] = r1;
+    R3[81] = (uint16) r1;
     for (i = 39; i >= 0; --i) {
         r2 = R4[i];
         r2 = (r2 << 8) | *--s;
@@ -159,7 +159,7 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x1541(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 6745);
         R3[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 6745); /* needed only for invalid inputs */
-        R3[2 * i + 1] = r1;
+        R3[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R3[81];
@@ -167,14 +167,14 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x1541(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 1314);
     R2[162] = r0;
     r1 = uint32_mod_uint14(r1, 1541); /* needed only for invalid inputs */
-    R2[163] = r1;
+    R2[163] = (uint16) r1;
     for (i = 80; i >= 0; --i) {
         r2 = R3[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 1314);
         R2[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 1314); /* needed only for invalid inputs */
-        R2[2 * i + 1] = r1;
+        R2[2 * i + 1] = (uint16) r1;
     }
 
     R1[326] = R2[163];
@@ -185,16 +185,16 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x1541(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 9277);
         R1[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 9277); /* needed only for invalid inputs */
-        R1[2 * i + 1] = r1;
+        R1[2 * i + 1] = (uint16) r1;
     }
 
-    R0[652] = 3 * R1[326] - 2310;
+    R0[652] = (int16) (3 * R1[326] - 2310);
     for (i = 325; i >= 0; --i) {
         r2 = R1[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 1541);
-        R0[2 * i] = 3 * r0 - 2310;
+        R0[2 * i] = (int16) (3 * r0 - 2310);
         r1 = uint32_mod_uint14(r1, 1541); /* needed only for invalid inputs */
-        R0[2 * i + 1] = 3 * r1 - 2310;
+        R0[2 * i + 1] = (int16) (3 * r1 - 2310);
     }
 }
diff --git a/crypto_kem/sntrup653/clean/crypto_decode_653x4621.c b/crypto_kem/sntrup653/clean/crypto_decode_653x4621.c
index 2bf05aaa..59a0b93e 100644
--- a/crypto_kem/sntrup653/clean/crypto_decode_653x4621.c
+++ b/crypto_kem/sntrup653/clean/crypto_decode_653x4621.c
@@ -30,7 +30,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
 
     *q = 0;
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 2^31 qpart <= xv <= 2^31 qpart + 2^31-1 */
     /* 2^31 qpart m <= xvm <= 2^31 qpart m + (2^31-1)m */
     /* 2^31 qpart m <= 2^31 x <= 2^31 qpart m + (2^31-1)m + x(m-1) */
@@ -42,7 +42,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += qpart;
     /* x <= 49146 */
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 0 <= newx <= (1-1/2^31)m + x(m-1)/2^31 */
     /* 0 <= newx <= m + 49146(2^14-1)/2^31 */
     /* 0 <= newx <= m + 0.4 */
@@ -59,7 +59,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += mask;
     /* x < m */
 
-    *r = x;
+    *r = (uint16) x;
 }
 
 static uint16 uint32_mod_uint14(uint32 x, uint16 m) {
@@ -80,7 +80,7 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x4621(void *v, const unsigned char
     r1 = 0;
     r1 = (r1 << 8) | *--s;
     r1 = uint32_mod_uint14(r1, 86); /* needed only for invalid inputs */
-    R10[0] = r1;
+    R10[0] = (uint16) r1;
 
     r2 = R10[0];
     r2 = (r2 << 8) | *--s;
@@ -88,7 +88,7 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x4621(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 835);
     R9[0] = r0;
     r1 = uint32_mod_uint14(r1, 6708); /* needed only for invalid inputs */
-    R9[1] = r1;
+    R9[1] = (uint16) r1;
 
     R8[2] = R9[1];
     r2 = R9[0];
@@ -97,19 +97,19 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x4621(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 7396);
     R8[0] = r0;
     r1 = uint32_mod_uint14(r1, 7396); /* needed only for invalid inputs */
-    R8[1] = r1;
+    R8[1] = (uint16) r1;
 
     r2 = R8[2];
     uint32_divmod_uint14(&r1, &r0, r2, 86);
     R7[4] = r0;
     r1 = uint32_mod_uint14(r1, 78); /* needed only for invalid inputs */
-    R7[5] = r1;
+    R7[5] = (uint16) r1;
     for (i = 1; i >= 0; --i) {
         r2 = R8[i];
         uint32_divmod_uint14(&r1, &r0, r2, 86);
         R7[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 86); /* needed only for invalid inputs */
-        R7[2 * i + 1] = r1;
+        R7[2 * i + 1] = (uint16) r1;
     }
 
     R6[10] = R7[5];
@@ -120,7 +120,7 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x4621(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 2370);
         R6[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 2370); /* needed only for invalid inputs */
-        R6[2 * i + 1] = r1;
+        R6[2 * i + 1] = (uint16) r1;
     }
 
     R5[20] = R6[10];
@@ -131,7 +131,7 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x4621(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 12461);
         R5[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 12461); /* needed only for invalid inputs */
-        R5[2 * i + 1] = r1;
+        R5[2 * i + 1] = (uint16) r1;
     }
 
     R4[40] = R5[20];
@@ -141,7 +141,7 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x4621(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 1786);
         R4[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 1786); /* needed only for invalid inputs */
-        R4[2 * i + 1] = r1;
+        R4[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R4[40];
@@ -150,14 +150,14 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x4621(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 676);
     R3[80] = r0;
     r1 = uint32_mod_uint14(r1, 7510); /* needed only for invalid inputs */
-    R3[81] = r1;
+    R3[81] = (uint16) r1;
     for (i = 39; i >= 0; --i) {
         r2 = R4[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 676);
         R3[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 676); /* needed only for invalid inputs */
-        R3[2 * i + 1] = r1;
+        R3[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R3[81];
@@ -165,14 +165,14 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x4621(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 416);
     R2[162] = r0;
     r1 = uint32_mod_uint14(r1, 4621); /* needed only for invalid inputs */
-    R2[163] = r1;
+    R2[163] = (uint16) r1;
     for (i = 80; i >= 0; --i) {
         r2 = R3[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 416);
         R2[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 416); /* needed only for invalid inputs */
-        R2[2 * i + 1] = r1;
+        R2[2 * i + 1] = (uint16) r1;
     }
 
     R1[326] = R2[163];
@@ -182,17 +182,17 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653x4621(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 326);
         R1[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 326); /* needed only for invalid inputs */
-        R1[2 * i + 1] = r1;
+        R1[2 * i + 1] = (uint16) r1;
     }
 
-    R0[652] = R1[326] - 2310;
+    R0[652] = (int16) (R1[326] - 2310);
     for (i = 325; i >= 0; --i) {
         r2 = R1[i];
         r2 = (r2 << 8) | *--s;
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 4621);
-        R0[2 * i] = r0 - 2310;
+        R0[2 * i] = (int16) (r0 - 2310);
         r1 = uint32_mod_uint14(r1, 4621); /* needed only for invalid inputs */
-        R0[2 * i + 1] = r1 - 2310;
+        R0[2 * i + 1] = (int16) (r1 - 2310);
     }
 }
diff --git a/crypto_kem/sntrup653/clean/crypto_decode_653xint16.c b/crypto_kem/sntrup653/clean/crypto_decode_653xint16.c
index 655095cd..33aea66a 100644
--- a/crypto_kem/sntrup653/clean/crypto_decode_653xint16.c
+++ b/crypto_kem/sntrup653/clean/crypto_decode_653xint16.c
@@ -8,8 +8,7 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_decode_653xint16(void *v, const unsigned cha
     for (i = 0; i < 653; ++i) {
         uint16_t u0 = s[0];
         uint16_t u1 = s[1];
-        u1 <<= 8;
-        *x = u0 | u1;
+        *x = (uint16_t) (u0 | (u1 << 8));
         x += 1;
         s += 2;
     }
diff --git a/crypto_kem/sntrup653/clean/crypto_encode_653x1541.c b/crypto_kem/sntrup653/clean/crypto_encode_653x1541.c
index 6b442cb2..1c04c23a 100644
--- a/crypto_kem/sntrup653/clean/crypto_encode_653x1541.c
+++ b/crypto_kem/sntrup653/clean/crypto_encode_653x1541.c
@@ -15,24 +15,24 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653x1541(unsigned char *out, const vo
     uint32 r2;
 
     for (i = 0; i < 326; ++i) {
-        r0 = (((R0[2 * i] + 2310) & 16383) * 10923) >> 15;
-        r1 = (((R0[2 * i + 1] + 2310) & 16383) * 10923) >> 15;
+        r0 = (uint16) ((((R0[2 * i] + 2310) & 16383) * 10923) >> 15);
+        r1 = (uint16) ((((R0[2 * i + 1] + 2310) & 16383) * 10923) >> 15);
         r2 = r0 + r1 * (uint32)1541;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
-    R[326] = (((R0[652] + 2310) & 16383) * 10923) >> 15;
+    R[326] = (uint16) ((((R0[652] + 2310) & 16383) * 10923) >> 15);
 
     for (i = 0; i < 163; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)9277;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[163] = R[326];
 
@@ -40,29 +40,29 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653x1541(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1314;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 41; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)6745;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 20; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)695;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[20] = R[40];
 
@@ -70,9 +70,9 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653x1541(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1887;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[10] = R[20];
 
@@ -80,11 +80,11 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653x1541(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)13910;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[5] = R[10];
 
@@ -92,36 +92,36 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653x1541(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)2953;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[4];
     r1 = R[5];
     r2 = r0 + r1 * (uint32)2953;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[2] = r2;
+    R[2] = (uint16) r2;
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)134;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)71;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/sntrup653/clean/crypto_encode_653x1541round.c b/crypto_kem/sntrup653/clean/crypto_encode_653x1541round.c
index b53d2dce..34256ac3 100644
--- a/crypto_kem/sntrup653/clean/crypto_encode_653x1541round.c
+++ b/crypto_kem/sntrup653/clean/crypto_encode_653x1541round.c
@@ -11,7 +11,7 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653x1541round(unsigned char *out, con
     int i;
 
     for (i = 0; i < p; ++i) {
-        x[i] = 3 * ((10923 * a[i] + 16384) >> 15);
+        x[i] = (int16) (3 * ((10923 * a[i] + 16384) >> 15));
     }
     PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653x1541(out, x);
 }
diff --git a/crypto_kem/sntrup653/clean/crypto_encode_653x3.c b/crypto_kem/sntrup653/clean/crypto_encode_653x3.c
index f6628a47..61ae2eed 100644
--- a/crypto_kem/sntrup653/clean/crypto_encode_653x3.c
+++ b/crypto_kem/sntrup653/clean/crypto_encode_653x3.c
@@ -11,9 +11,9 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653x3(unsigned char *s, const void *v
 
     for (i = 0; i < p / 4; ++i) {
         x = *f++ + 1;
-        x += (*f++ + 1) << 2;
-        x += (*f++ + 1) << 4;
-        x += (*f++ + 1) << 6;
+        x += (uint8) ((*f++ + 1) << 2);
+        x += (uint8) ((*f++ + 1) << 4);
+        x += (uint8) ((*f++ + 1) << 6);
         *s++ = x;
     }
     x = *f++ + 1;
diff --git a/crypto_kem/sntrup653/clean/crypto_encode_653x4621.c b/crypto_kem/sntrup653/clean/crypto_encode_653x4621.c
index 7c3f120f..09d6378f 100644
--- a/crypto_kem/sntrup653/clean/crypto_encode_653x4621.c
+++ b/crypto_kem/sntrup653/clean/crypto_encode_653x4621.c
@@ -18,11 +18,11 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653x4621(unsigned char *out, const vo
         r0 = (R0[2 * i] + 2310) & 16383;
         r1 = (R0[2 * i + 1] + 2310) & 16383;
         r2 = r0 + r1 * (uint32)4621;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[326] = (R0[652] + 2310) & 16383;
 
@@ -30,9 +30,9 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653x4621(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)326;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[163] = R[326];
 
@@ -40,35 +40,35 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653x4621(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)416;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 40; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)676;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[80];
     r1 = R[81];
     r2 = r0 + r1 * (uint32)676;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[40] = r2;
+    R[40] = (uint16) r2;
 
     for (i = 0; i < 20; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1786;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[20] = R[40];
 
@@ -76,11 +76,11 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653x4621(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)12461;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[10] = R[20];
 
@@ -88,11 +88,11 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653x4621(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)2370;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[5] = R[10];
 
@@ -100,28 +100,28 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653x4621(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)86;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)7396;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)835;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/sntrup653/clean/crypto_encode_653xfreeze3.c b/crypto_kem/sntrup653/clean/crypto_encode_653xfreeze3.c
index b938d071..58ceed32 100644
--- a/crypto_kem/sntrup653/clean/crypto_encode_653xfreeze3.c
+++ b/crypto_kem/sntrup653/clean/crypto_encode_653xfreeze3.c
@@ -12,7 +12,7 @@
 /* and F3_freeze(x) is in {-2,-1,0,1,2} */
 
 static inline unsigned char F3_freeze(int16 x) {
-    return x - 3 * ((10923 * x + 16384) >> 15);
+    return (unsigned char) (x - 3 * ((10923 * x + 16384) >> 15));
 }
 
 void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653xfreeze3(unsigned char *s, const void *v) {
diff --git a/crypto_kem/sntrup653/clean/crypto_encode_653xint16.c b/crypto_kem/sntrup653/clean/crypto_encode_653xint16.c
index 8555ae26..d543b0c1 100644
--- a/crypto_kem/sntrup653/clean/crypto_encode_653xint16.c
+++ b/crypto_kem/sntrup653/clean/crypto_encode_653xint16.c
@@ -7,7 +7,7 @@ void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_653xint16(unsigned char *s, const voi
 
     for (i = 0; i < 653; ++i) {
         uint16_t u = *x++;
-        *s++ = u;
-        *s++ = u >> 8;
+        *s++ = (unsigned char) u;
+        *s++ = (unsigned char) (u >> 8);
     }
 }
diff --git a/crypto_kem/sntrup653/clean/crypto_encode_int16.c b/crypto_kem/sntrup653/clean/crypto_encode_int16.c
index 01d126c0..36c5d9b4 100644
--- a/crypto_kem/sntrup653/clean/crypto_encode_int16.c
+++ b/crypto_kem/sntrup653/clean/crypto_encode_int16.c
@@ -4,6 +4,6 @@
 
 void PQCLEAN_SNTRUP653_CLEAN_crypto_encode_int16(unsigned char *s, const void *x) {
     uint16 u = *(const uint16 *) x;
-    s[0] = u;
-    s[1] = u >> 8;
+    s[0] = (unsigned char) u;
+    s[1] = (unsigned char) (u >> 8);
 }
diff --git a/crypto_kem/sntrup653/clean/kem.c b/crypto_kem/sntrup653/clean/kem.c
index 9ade99fb..c589097c 100644
--- a/crypto_kem/sntrup653/clean/kem.c
+++ b/crypto_kem/sntrup653/clean/kem.c
@@ -65,7 +65,7 @@ static void Rq_recip3(Fq *out, const small *in) {
 static void Hash(unsigned char *out, const unsigned char *in, int inlen) {
     unsigned char h[64];
     int i;
-    sha512(h, in, inlen);
+    sha512(h, in, (size_t) inlen);
     for (i = 0; i < 32; ++i) {
         out[i] = h[i];
     }
@@ -103,7 +103,7 @@ static void Short_random(small *out) {
     }
     PQCLEAN_SNTRUP653_CLEAN_crypto_sort_uint32(L, ppadsort);
     for (i = 0; i < p; ++i) {
-        out[i] = (L[i] & 3) - 1;
+        out[i] = (small) ((L[i] & 3) - 1);
     }
 }
 
@@ -115,7 +115,7 @@ static void Small_random(small *out) {
         L[i] = urandom32();
     }
     for (i = 0; i < p; ++i) {
-        out[i] = (((L[i] & 0x3fffffff) * 3) >> 30) - 1;
+        out[i] = (small) ((((L[i] & 0x3fffffff) * 3) >> 30) - 1);
     }
 }
 
@@ -248,13 +248,13 @@ int PQCLEAN_SNTRUP653_CLEAN_crypto_kem_dec(unsigned char *k, const unsigned char
         Hide(x, cnew, r_enc, r, pk, cache);
         mask = crypto_verify_clen(c, cnew);
         for (i = 0; i < Small_bytes; ++i) {
-            r_enc[i + 1] ^= mask & (r_enc[i + 1] ^ rho[i]);
+            r_enc[i + 1] ^= (unsigned char) (mask & (r_enc[i + 1] ^ rho[i]));
         }
         Hash(x + 1, r_enc, 1 + Small_bytes); /* XXX: can instead do cmov on cached hash of rho */
         for (i = 0; i < Ciphertexts_bytes + Confirm_bytes; ++i) {
             x[1 + Hash_bytes + i] = c[i];
         }
-        x[0] = 1 + mask;
+        x[0] = (unsigned char) (1 + mask);
         Hash(k, x, sizeof x);
     }
     return 0;
diff --git a/crypto_kem/sntrup761/avx2/Makefile b/crypto_kem/sntrup761/avx2/Makefile
index 3e1c7ac2..2336c9db 100644
--- a/crypto_kem/sntrup761/avx2/Makefile
+++ b/crypto_kem/sntrup761/avx2/Makefile
@@ -4,7 +4,7 @@ LIB=libsntrup761_avx2.a
 HEADERS=api.h crypto_core_inv3sntrup761.h crypto_core_invsntrup761.h crypto_core_mult3sntrup761.h crypto_core_multsntrup761.h crypto_core_multsntrup761_ntt.h crypto_core_scale3sntrup761.h crypto_core_weightsntrup761.h crypto_core_wforcesntrup761.h crypto_decode_761x1531.h crypto_decode_761x3.h crypto_decode_761x4591.h crypto_decode_761xint16.h crypto_decode_761xint32.h crypto_decode_int16.h crypto_encode_761x1531.h crypto_encode_761x1531round.h crypto_encode_761x3.h crypto_encode_761x4591.h crypto_encode_761xfreeze3.h crypto_encode_761xint16.h crypto_encode_int16.h crypto_sort_int32.h crypto_sort_uint32.h crypto_stream_aes256ctr.h crypto_verify_1039.h params.h 
 OBJECTS=crypto_core_inv3sntrup761.o crypto_core_invsntrup761.o crypto_core_mult3sntrup761.o crypto_core_multsntrup761.o crypto_core_multsntrup761_ntt.o crypto_core_scale3sntrup761.o crypto_core_weightsntrup761.o crypto_core_wforcesntrup761.o crypto_decode_761x1531.o crypto_decode_761x3.o crypto_decode_761x4591.o crypto_decode_761xint16.o crypto_decode_761xint32.o crypto_decode_int16.o crypto_encode_761x1531.o crypto_encode_761x1531round.o crypto_encode_761x3.o crypto_encode_761x4591.o crypto_encode_761xfreeze3.o crypto_encode_761xint16.o crypto_encode_int16.o crypto_sort_int32.o crypto_sort_uint32.o crypto_stream_aes256ctr.o crypto_verify_1039.o kem.o 
 
-CFLAGS=-O3 -mavx2 -mbmi2 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -std=c99 -I../../../common $(EXTRAFLAGS)
+CFLAGS=-O3 -mavx2 -mbmi2 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -Wconversion -std=c99 -I../../../common $(EXTRAFLAGS)
 
 all: $(LIB)
 
diff --git a/crypto_kem/sntrup761/avx2/crypto_core_inv3sntrup761.c b/crypto_kem/sntrup761/avx2/crypto_core_inv3sntrup761.c
index 71fdf508..03c327eb 100644
--- a/crypto_kem/sntrup761/avx2/crypto_core_inv3sntrup761.c
+++ b/crypto_kem/sntrup761/avx2/crypto_core_inv3sntrup761.c
@@ -179,7 +179,7 @@ static void vec256_final(small *out, const vec256 *V0, const vec256 *V1) {
     vec256_tobits(V1, v1);
 
     for (i = 0; i < ppad; ++i) {
-        v[i] = v0[i] + 2 * v1[i] - 4 * (v0[i] & v1[i]);
+        v[i] = (small) (v0[i] + 2 * v1[i] - 4 * (v0[i] & v1[i]));
     }
 
     for (i = 0; i < ppad; ++i) {
@@ -252,11 +252,11 @@ static inline int vec256_bit0mask(vec256 *f) {
 static inline void vec256_divx_1(vec256 *f) {
     vec256 f0 = f[0];
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
 
     low0 = low0 >> 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
 
     f[0] = _mm256_permute4x64_epi64(f0, 0x39);
 }
@@ -265,14 +265,14 @@ static inline void vec256_divx_2(vec256 *f) {
     vec256 f0 = f[0];
     vec256 f1 = f[1];
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
-    unsigned long long low1 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low1 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
 
     low0 = (low0 >> 1) | (low1 << 63);
     low1 = low1 >> 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
-    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, low1), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
+    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, (long long) low1), 0x3);
 
     f[0] = _mm256_permute4x64_epi64(f0, 0x39);
     f[1] = _mm256_permute4x64_epi64(f1, 0x39);
@@ -283,17 +283,17 @@ static inline void vec256_divx_3(vec256 *f) {
     vec256 f1 = f[1];
     vec256 f2 = f[2];
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
-    unsigned long long low1 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
-    unsigned long long low2 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low1 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
+    unsigned long long low2 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
 
     low0 = (low0 >> 1) | (low1 << 63);
     low1 = (low1 >> 1) | (low2 << 63);
     low2 = low2 >> 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
-    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, low1), 0x3);
-    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, low2), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
+    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, (long long) low1), 0x3);
+    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, (long long) low2), 0x3);
 
     f[0] = _mm256_permute4x64_epi64(f0, 0x39);
     f[1] = _mm256_permute4x64_epi64(f1, 0x39);
@@ -303,11 +303,11 @@ static inline void vec256_divx_3(vec256 *f) {
 static inline void vec256_timesx_1(vec256 *f) {
     vec256 f0 = _mm256_permute4x64_epi64(f[0], 0x93);
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
 
     low0 = low0 << 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
 
     f[0] = f0;
 }
@@ -316,14 +316,14 @@ static inline void vec256_timesx_2(vec256 *f) {
     vec256 f0 = _mm256_permute4x64_epi64(f[0], 0x93);
     vec256 f1 = _mm256_permute4x64_epi64(f[1], 0x93);
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
-    unsigned long long low1 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low1 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
 
     low1 = (low1 << 1) | (low0 >> 63);
     low0 = low0 << 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
-    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, low1), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
+    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, (long long) low1), 0x3);
 
     f[0] = f0;
     f[1] = f1;
@@ -336,7 +336,7 @@ static inline void vec256_timesx_3(vec256 *f) {
 
     unsigned long long low0 = *(unsigned long long *) &f0;
     unsigned long long low1 = *(unsigned long long *) &f1;
-    unsigned long long low2 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
+    unsigned long long low2 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
 
     low2 = (low2 << 1) | (low1 >> 63);
     low1 = (low1 << 1) | (low0 >> 63);
@@ -344,7 +344,7 @@ static inline void vec256_timesx_3(vec256 *f) {
 
     *(unsigned long long *) &f0 = low0;
     *(unsigned long long *) &f1 = low1;
-    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, low2), 0x3);
+    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, (long long) low2), 0x3);
 
     f[0] = f0;
     f[1] = f1;
@@ -537,6 +537,6 @@ int PQCLEAN_SNTRUP761_AVX2_crypto_core_inv3sntrup761(unsigned char *outbytes, co
     vec256_scale(V0, V1, c0vec, c1vec);
 
     vec256_final(out, V0, V1);
-    out[p] = negative_mask(minusdelta);
+    out[p] = (small) negative_mask(minusdelta);
     return 0;
 }
diff --git a/crypto_kem/sntrup761/avx2/crypto_core_invsntrup761.c b/crypto_kem/sntrup761/avx2/crypto_core_invsntrup761.c
index 6fdd9e0d..7ef48607 100644
--- a/crypto_kem/sntrup761/avx2/crypto_core_invsntrup761.c
+++ b/crypto_kem/sntrup761/avx2/crypto_core_invsntrup761.c
@@ -14,11 +14,11 @@
 
 /* return -1 if x!=0; else return 0 */
 static int int16_nonzero_mask(int16 x) {
-    uint16 u = x; /* 0, else 1...65535 */
+    uint16 u = (uint16) x; /* 0, else 1...65535 */
     uint32 v = u; /* 0, else 1...65535 */
     v = -v; /* 0, else 2^32-65535...2^32-1 */
     v >>= 31; /* 0, else 1 */
-    return -v; /* 0, else -1 */
+    return -(int) v; /* 0, else -1 */
 }
 
 /* return -1 if x<0; otherwise return 0 */
@@ -37,7 +37,7 @@ typedef int16 Fq;
 static Fq Fq_freeze(int32 x) {
     x -= q * ((q18 * x) >> 18);
     x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    return (Fq) x;
 }
 
 /* nonnegative e */
@@ -158,13 +158,13 @@ int PQCLEAN_SNTRUP761_AVX2_crypto_core_invsntrup761(unsigned char *outbytes, con
         f0 = f[0];
 
         minusdelta = -delta;
-        swap = int16_negative_mask(minusdelta) & int16_nonzero_mask(g0);
+        swap = int16_negative_mask((int16) minusdelta) & int16_nonzero_mask(g0);
         delta ^= swap & (delta ^ minusdelta);
         delta += 1;
 
         fgflip = swap & (f0 ^ g0);
-        f0 ^= fgflip;
-        g0 ^= fgflip;
+        f0 ^= (Fq) fgflip;
+        g0 ^= (Fq) fgflip;
 
         f[0] = f0;
 
@@ -177,13 +177,13 @@ int PQCLEAN_SNTRUP761_AVX2_crypto_core_invsntrup761(unsigned char *outbytes, con
         f0 = f[0];
 
         minusdelta = -delta;
-        swap = int16_negative_mask(minusdelta) & int16_nonzero_mask(g0);
+        swap = int16_negative_mask((int16) minusdelta) & int16_nonzero_mask(g0);
         delta ^= swap & (delta ^ minusdelta);
         delta += 1;
 
         fgflip = swap & (f0 ^ g0);
-        f0 ^= fgflip;
-        g0 ^= fgflip;
+        f0 ^= (Fq) fgflip;
+        g0 ^= (Fq) fgflip;
 
         f[0] = f0;
 
@@ -197,6 +197,6 @@ int PQCLEAN_SNTRUP761_AVX2_crypto_core_invsntrup761(unsigned char *outbytes, con
     }
 
     crypto_encode_pxint16(outbytes, out);
-    outbytes[2 * p] = int16_nonzero_mask(delta);
+    outbytes[2 * p] = (unsigned char) int16_nonzero_mask((int16) delta);
     return 0;
 }
diff --git a/crypto_kem/sntrup761/avx2/crypto_core_mult3sntrup761.c b/crypto_kem/sntrup761/avx2/crypto_core_mult3sntrup761.c
index ad5b13ec..4a6ddcdc 100644
--- a/crypto_kem/sntrup761/avx2/crypto_core_mult3sntrup761.c
+++ b/crypto_kem/sntrup761/avx2/crypto_core_mult3sntrup761.c
@@ -229,14 +229,14 @@ int PQCLEAN_SNTRUP761_AVX2_crypto_core_mult3sntrup761(unsigned char *outbytes, c
     }
 
     for (i = 0; i < p; ++i) {
-        int8 fi = inbytes[i];
+        int8 fi = (int8) inbytes[i];
         int8 fi0 = fi & 1;
-        f[i] = fi0 - (fi & (fi0 << 1));
+        f[i] = (int16) (fi0 - (fi & (fi0 << 1)));
     }
     for (i = 0; i < p; ++i) {
-        int8 gi = kbytes[i];
+        int8 gi = (int8) kbytes[i];
         int8 gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (int16) (gi0 - (gi & (gi0 << 1)));
     }
 
     mult768(fg, f, g);
@@ -252,7 +252,7 @@ int PQCLEAN_SNTRUP761_AVX2_crypto_core_mult3sntrup761(unsigned char *outbytes, c
     }
 
     for (i = 0; i < p; ++i) {
-        outbytes[i] = h[i];
+        outbytes[i] = (unsigned char) h[i];
     }
 
     return 0;
diff --git a/crypto_kem/sntrup761/avx2/crypto_core_multsntrup761.c b/crypto_kem/sntrup761/avx2/crypto_core_multsntrup761.c
index 58b83ed2..87253477 100644
--- a/crypto_kem/sntrup761/avx2/crypto_core_multsntrup761.c
+++ b/crypto_kem/sntrup761/avx2/crypto_core_multsntrup761.c
@@ -291,9 +291,9 @@ int PQCLEAN_SNTRUP761_AVX2_crypto_core_multsntrup761(unsigned char *outbytes, co
         store_x16(&f[i], x);
     }
     for (i = 0; i < p; ++i) {
-        int8 gi = kbytes[i];
+        int8 gi = (int8) kbytes[i];
         int8 gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (int16) (gi0 - (gi & (gi0 << 1)));
     }
 
     mult768(fg, f, g);
diff --git a/crypto_kem/sntrup761/avx2/crypto_core_weightsntrup761.c b/crypto_kem/sntrup761/avx2/crypto_core_weightsntrup761.c
index 3398fe2f..2184979d 100644
--- a/crypto_kem/sntrup761/avx2/crypto_core_weightsntrup761.c
+++ b/crypto_kem/sntrup761/avx2/crypto_core_weightsntrup761.c
@@ -36,8 +36,8 @@ int PQCLEAN_SNTRUP761_AVX2_crypto_core_weightsntrup761(unsigned char *outbytes,
     sum = _mm256_hadd_epi16(sum, sum);
     /* want sum[0]+sum[8] */
 
-    weight = _mm256_extract_epi16(sum, 0);
-    weight += _mm256_extract_epi16(sum, 8);
+    weight = (int16) _mm256_extract_epi16(sum, 0);
+    weight += (int16) _mm256_extract_epi16(sum, 8);
 
     PQCLEAN_SNTRUP761_AVX2_crypto_encode_int16(outbytes, &weight);
     return 0;
diff --git a/crypto_kem/sntrup761/avx2/crypto_core_wforcesntrup761.c b/crypto_kem/sntrup761/avx2/crypto_core_wforcesntrup761.c
index 0a89659a..0dedf0af 100644
--- a/crypto_kem/sntrup761/avx2/crypto_core_wforcesntrup761.c
+++ b/crypto_kem/sntrup761/avx2/crypto_core_wforcesntrup761.c
@@ -17,7 +17,7 @@ int PQCLEAN_SNTRUP761_AVX2_crypto_core_wforcesntrup761(unsigned char *out, const
     crypto_core_weight((unsigned char *) &weight, in);
     PQCLEAN_SNTRUP761_AVX2_crypto_decode_int16(&weight, (unsigned char *) &weight);
 
-    mask = (weight - w) | (w - weight);
+    mask = (int16) ((weight - w) | (w - weight));
     mask >>= 15;
     maskvec = _mm256_set1_epi16((short) ~mask);
 
diff --git a/crypto_kem/sntrup761/avx2/crypto_decode_761x1531.c b/crypto_kem/sntrup761/avx2/crypto_decode_761x1531.c
index 83dae782..7de1f43d 100644
--- a/crypto_kem/sntrup761/avx2/crypto_decode_761x1531.c
+++ b/crypto_kem/sntrup761/avx2/crypto_decode_761x1531.c
@@ -10,7 +10,7 @@ static inline int16 mullo(int16 x, int16 y) {
 }
 
 static inline int16 mulhi(int16 x, int16 y) {
-    return (x * (int32)y) >> 16;
+    return (int16) ((x * (int32)y) >> 16);
 }
 
 static inline __m256i add(__m256i x, __m256i y) {
@@ -78,7 +78,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
     a0 = mulhi(a0, 60) - mulhi(mullo(a0, -28292), 593); /* -297...311 */
     a0 += s[1 * i + 0]; /* -297...566 */
     a0 += (a0 >> 15) & 593; /* 0...592 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, -31055);
 
     /* invalid inputs might need reduction mod 1500 */
@@ -100,7 +100,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
         a0 = mulhi(a0, 672) - mulhi(mullo(a0, -2692), 6232); /* -3148...3152 */
         a0 += s[2 * i + 0]; /* -3148...3407 */
         a0 += (a0 >> 15) & 6232; /* 0...6231 */
-        a1 = (a2 << 13) + (s[2 * i + 1] << 5) + ((s[2 * i] - a0) >> 3);
+        a1 = (int16) ((a2 << 13) + (s[2 * i + 1] << 5) + ((s[2 * i] - a0) >> 3));
         a1 = mullo(a1, 12451);
 
         /* invalid inputs might need reduction mod 6232 */
@@ -119,7 +119,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
     a0 = mulhi(a0, -476) - mulhi(mullo(a0, -13284), 1263); /* -751...631 */
     a0 += s[1 * i + 0]; /* -751...886 */
     a0 += (a0 >> 15) & 1263; /* 0...1262 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, -22001);
 
     /* invalid inputs might need reduction mod 304 */
@@ -134,7 +134,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
         a0 = mulhi(a0, -476) - mulhi(mullo(a0, -13284), 1263); /* -751...631 */
         a0 += s[1 * i + 0]; /* -751...886 */
         a0 += (a0 >> 15) & 1263; /* 0...1262 */
-        a1 = (a2 << 8) + s[i] - a0;
+        a1 = (int16) ((a2 << 8) + s[i] - a0);
         a1 = mullo(a1, -22001);
 
         /* invalid inputs might need reduction mod 1263 */
@@ -155,7 +155,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
     a0 = mulhi(a0, 2348) - mulhi(mullo(a0, -1844), 9097); /* -4712...4741 */
     a0 += s[2 * i + 0]; /* -4712...4996 */
     a0 += (a0 >> 15) & 9097; /* 0...9096 */
-    a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+    a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
     a1 = mullo(a1, 17081);
 
     /* invalid inputs might need reduction mod 2188 */
@@ -172,7 +172,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
         a0 = mulhi(a0, 2348) - mulhi(mullo(a0, -1844), 9097); /* -4712...4741 */
         a0 += s[2 * i + 0]; /* -4712...4996 */
         a0 += (a0 >> 15) & 9097; /* 0...9096 */
-        a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+        a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
         a1 = mullo(a1, 17081);
 
         /* invalid inputs might need reduction mod 9097 */
@@ -191,7 +191,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
     a0 = mulhi(a0, 372) - mulhi(mullo(a0, -10994), 1526); /* -763...856 */
     a0 += s[1 * i + 0]; /* -763...1111 */
     a0 += (a0 >> 15) & 1526; /* 0...1525 */
-    a1 = (a2 << 7) + ((s[i] - a0) >> 1);
+    a1 = (int16) ((a2 << 7) + ((s[i] - a0) >> 1));
     a1 = mullo(a1, -18381);
 
     /* invalid inputs might need reduction mod 367 */
@@ -206,7 +206,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
         a0 = mulhi(a0, 372) - mulhi(mullo(a0, -10994), 1526); /* -763...856 */
         a0 += s[1 * i + 0]; /* -763...1111 */
         a0 += (a0 >> 15) & 1526; /* 0...1525 */
-        a1 = (a2 << 7) + ((s[i] - a0) >> 1);
+        a1 = (int16) ((a2 << 7) + ((s[i] - a0) >> 1));
         a1 = mullo(a1, -18381);
 
         /* invalid inputs might need reduction mod 1526 */
@@ -225,7 +225,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
     a0 = mulhi(a0, -284) - mulhi(mullo(a0, -26844), 625); /* -384...312 */
     a0 += s[1 * i + 0]; /* -384...567 */
     a0 += (a0 >> 15) & 625; /* 0...624 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, 32401);
 
     /* invalid inputs might need reduction mod 150 */
@@ -276,7 +276,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
     a0 = mulhi(a0, 2816) - mulhi(mullo(a0, -2621), 6400); /* -3338...3378 */
     a0 += s[2 * i + 0]; /* -3338...3633 */
     a0 += (a0 >> 15) & 6400; /* 0...6399 */
-    a1 = (a2 << 8) + s[2 * i + 1] + ((s[2 * i] - a0) >> 8);
+    a1 = (int16) ((a2 << 8) + s[2 * i + 1] + ((s[2 * i] - a0) >> 8));
     a1 = mullo(a1, 23593);
 
     /* invalid inputs might need reduction mod 1531 */
@@ -397,7 +397,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x1531(void *v, const unsigned char
 
     /* R1 ------> R0: reconstruct mod 761*[1531] */
 
-    R0[760] = 3 * R1[380] - 2295;
+    R0[760] = (int16) (3 * R1[380] - 2295);
     s -= 380;
     i = 364;
     for (;;) {
diff --git a/crypto_kem/sntrup761/avx2/crypto_decode_761x4591.c b/crypto_kem/sntrup761/avx2/crypto_decode_761x4591.c
index 35cd3196..c8e3bfbc 100644
--- a/crypto_kem/sntrup761/avx2/crypto_decode_761x4591.c
+++ b/crypto_kem/sntrup761/avx2/crypto_decode_761x4591.c
@@ -10,7 +10,7 @@ static inline int16 mullo(int16 x, int16 y) {
 }
 
 static inline int16 mulhi(int16 x, int16 y) {
-    return (x * (int32)y) >> 16;
+    return (int16) ((x * (int32)y) >> 16);
 }
 
 static inline __m256i add(__m256i x, __m256i y) {
@@ -80,7 +80,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x4591(void *v, const unsigned char
     a0 = mulhi(a0, -3624) - mulhi(mullo(a0, -1772), 9470); /* -5011...5046 */
     a0 += s[2 * i + 0]; /* -5011...5301 */
     a0 += (a0 >> 15) & 9470; /* 0...9469 */
-    a1 = (a2 << 15) + (s[2 * i + 1] << 7) + ((s[2 * i] - a0) >> 1);
+    a1 = (int16) ((a2 << 15) + (s[2 * i + 1] << 7) + ((s[2 * i] - a0) >> 1));
     a1 = mullo(a1, -21121);
 
     /* invalid inputs might need reduction mod 11127 */
@@ -100,7 +100,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x4591(void *v, const unsigned char
         a0 = mulhi(a0, 541) - mulhi(mullo(a0, -10775), 1557); /* -779...913 */
         a0 += s[1 * i + 0]; /* -779...1168 */
         a0 += (a0 >> 15) & 1557; /* 0...1556 */
-        a1 = (a2 << 8) + s[i] - a0;
+        a1 = (int16) ((a2 << 8) + s[i] - a0);
         a1 = mullo(a1, -26307);
 
         /* invalid inputs might need reduction mod 1557 */
@@ -119,7 +119,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x4591(void *v, const unsigned char
     a0 = mulhi(a0, -545) - mulhi(mullo(a0, -1661), 10101); /* -5187...5050 */
     a0 += s[1 * i + 0]; /* -5187...5305 */
     a0 += (a0 >> 15) & 10101; /* 0...10100 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, 12509);
 
     /* invalid inputs might need reduction mod 282 */
@@ -136,7 +136,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x4591(void *v, const unsigned char
         a0 = mulhi(a0, -545) - mulhi(mullo(a0, -1661), 10101); /* -5095...5093 */
         a0 += s[2 * i + 0]; /* -5095...5348 */
         a0 += (a0 >> 15) & 10101; /* 0...10100 */
-        a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+        a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
         a1 = mullo(a1, 12509);
 
         /* invalid inputs might need reduction mod 10101 */
@@ -157,7 +157,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x4591(void *v, const unsigned char
     a0 = mulhi(a0, -656) - mulhi(mullo(a0, -10434), 1608); /* -815...813 */
     a0 += s[2 * i + 0]; /* -815...1068 */
     a0 += (a0 >> 15) & 1608; /* 0...1607 */
-    a1 = (a2 << 13) + (s[2 * i + 1] << 5) + ((s[2 * i] - a0) >> 3);
+    a1 = (int16) ((a2 << 13) + (s[2 * i + 1] << 5) + ((s[2 * i] - a0) >> 3));
     a1 = mullo(a1, 6521);
 
     /* invalid inputs might need reduction mod 11468 */
@@ -172,7 +172,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x4591(void *v, const unsigned char
         a0 = mulhi(a0, -656) - mulhi(mullo(a0, -10434), 1608); /* -968...804 */
         a0 += s[1 * i + 0]; /* -968...1059 */
         a0 += (a0 >> 15) & 1608; /* 0...1607 */
-        a1 = (a2 << 5) + ((s[i] - a0) >> 3);
+        a1 = (int16) ((a2 << 5) + ((s[i] - a0) >> 3));
         a1 = mullo(a1, 6521);
 
         /* invalid inputs might need reduction mod 1608 */
@@ -191,7 +191,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x4591(void *v, const unsigned char
     a0 = mulhi(a0, 4206) - mulhi(mullo(a0, -1634), 10265); /* -5133...6184 */
     a0 += s[1 * i + 0]; /* -5133...6439 */
     a0 += (a0 >> 15) & 10265; /* 0...10264 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, -19415);
 
     /* invalid inputs might need reduction mod 286 */
@@ -208,7 +208,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x4591(void *v, const unsigned char
         a0 = mulhi(a0, 4206) - mulhi(mullo(a0, -1634), 10265); /* -5462...5545 */
         a0 += s[2 * i + 0]; /* -5462...5800 */
         a0 += (a0 >> 15) & 10265; /* 0...10264 */
-        a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+        a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
         a1 = mullo(a1, -19415);
 
         /* invalid inputs might need reduction mod 10265 */
@@ -229,7 +229,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x4591(void *v, const unsigned char
     a0 = mulhi(a0, -134) - mulhi(mullo(a0, -10350), 1621); /* -813...812 */
     a0 += s[2 * i + 0]; /* -813...1067 */
     a0 += (a0 >> 15) & 1621; /* 0...1620 */
-    a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+    a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
     a1 = mullo(a1, -14595);
 
     /* invalid inputs might need reduction mod 11550 */
@@ -278,7 +278,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761x4591(void *v, const unsigned char
     a0 = mulhi(a0, -272) - mulhi(mullo(a0, -26052), 644); /* -390...322 */
     a0 += s[1 * i + 0]; /* -390...577 */
     a0 += (a0 >> 15) & 644; /* 0...643 */
-    a1 = (a2 << 6) + ((s[i] - a0) >> 2);
+    a1 = (int16) ((a2 << 6) + ((s[i] - a0) >> 2));
     a1 = mullo(a1, -7327);
 
     /* invalid inputs might need reduction mod 4591 */
diff --git a/crypto_kem/sntrup761/avx2/crypto_decode_761xint16.c b/crypto_kem/sntrup761/avx2/crypto_decode_761xint16.c
index 4b323850..68210a2c 100644
--- a/crypto_kem/sntrup761/avx2/crypto_decode_761xint16.c
+++ b/crypto_kem/sntrup761/avx2/crypto_decode_761xint16.c
@@ -8,8 +8,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_decode_761xint16(void *v, const unsigned char
     for (i = 0; i < 761; ++i) {
         uint16_t u0 = s[0];
         uint16_t u1 = s[1];
-        u1 <<= 8;
-        *x = u0 | u1;
+        *x = (uint16_t) (u0 | (u1 << 8));
         x += 1;
         s += 2;
     }
diff --git a/crypto_kem/sntrup761/avx2/crypto_decode_int16.c b/crypto_kem/sntrup761/avx2/crypto_decode_int16.c
index 3e4bf8ef..3994a7e5 100644
--- a/crypto_kem/sntrup761/avx2/crypto_decode_int16.c
+++ b/crypto_kem/sntrup761/avx2/crypto_decode_int16.c
@@ -4,6 +4,6 @@
 void PQCLEAN_SNTRUP761_AVX2_crypto_decode_int16(void *x, const unsigned char *s) {
     uint16_t u0 = s[0];
     uint16_t u1 = s[1];
-    u1 <<= 8;
+    u1 = (uint16_t) (u1 << 8);
     *(uint16_t *) x = u0 | u1;
 }
diff --git a/crypto_kem/sntrup761/avx2/crypto_encode_761x1531.c b/crypto_kem/sntrup761/avx2/crypto_encode_761x1531.c
index c5a03da4..eeff059c 100644
--- a/crypto_kem/sntrup761/avx2/crypto_encode_761x1531.c
+++ b/crypto_kem/sntrup761/avx2/crypto_encode_761x1531.c
@@ -42,26 +42,26 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_encode_761x1531(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
-    R[380] = (((R0[760] + 2295) & 16383) * 10923) >> 15;
+    R[380] = (uint16) ((((R0[760] + 2295) & 16383) * 10923) >> 15);
 
     reading = (uint16 *) R;
     writing = R;
@@ -124,22 +124,22 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_encode_761x1531(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -195,22 +195,22 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_encode_761x1531(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -237,22 +237,22 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_encode_761x1531(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -261,41 +261,41 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_encode_761x1531(unsigned char *out, const voi
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)9097;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 3; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1263;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)6232;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)593;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/sntrup761/avx2/crypto_encode_761x1531round.c b/crypto_kem/sntrup761/avx2/crypto_encode_761x1531round.c
index ab045dbd..0687a689 100644
--- a/crypto_kem/sntrup761/avx2/crypto_encode_761x1531round.c
+++ b/crypto_kem/sntrup761/avx2/crypto_encode_761x1531round.c
@@ -44,26 +44,26 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_encode_761x1531round(unsigned char *out, cons
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
-    R[380] = (((3 * ((10923 * R0[760] + 16384) >> 15) + 2295) & 16383) * 10923) >> 15;
+    R[380] = (uint16) ((((3 * ((10923 * R0[760] + 16384) >> 15) + 2295) & 16383) * 10923) >> 15);
 
     reading = (uint16 *) R;
     writing = R;
@@ -126,22 +126,22 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_encode_761x1531round(unsigned char *out, cons
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -197,22 +197,22 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_encode_761x1531round(unsigned char *out, cons
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -239,22 +239,22 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_encode_761x1531round(unsigned char *out, cons
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -263,41 +263,41 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_encode_761x1531round(unsigned char *out, cons
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)9097;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 3; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1263;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)6232;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)593;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/sntrup761/avx2/crypto_encode_761x4591.c b/crypto_kem/sntrup761/avx2/crypto_encode_761x4591.c
index 7d87488f..20bafd0e 100644
--- a/crypto_kem/sntrup761/avx2/crypto_encode_761x4591.c
+++ b/crypto_kem/sntrup761/avx2/crypto_encode_761x4591.c
@@ -82,22 +82,22 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_encode_761x4591(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -125,22 +125,22 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_encode_761x4591(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -163,22 +163,22 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_encode_761x4591(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -205,104 +205,104 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_encode_761x4591(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
     r0 = R[46];
     r1 = R[47];
     r2 = r0 + r1 * (uint32)1621;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[23] = r2;
+    R[23] = (uint16) r2;
 
     for (i = 0; i < 11; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)10265;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[22];
     r1 = R[23];
     r2 = r0 + r1 * (uint32)10265;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[11] = r2;
+    R[11] = (uint16) r2;
 
     for (i = 0; i < 5; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1608;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[10];
     r1 = R[11];
     r2 = r0 + r1 * (uint32)1608;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[5] = r2;
+    R[5] = (uint16) r2;
 
     for (i = 0; i < 2; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)10101;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[4];
     r1 = R[5];
     r2 = r0 + r1 * (uint32)10101;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[2] = r2;
+    R[2] = (uint16) r2;
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)1557;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)9470;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/sntrup761/avx2/crypto_encode_761xint16.c b/crypto_kem/sntrup761/avx2/crypto_encode_761xint16.c
index ba851932..db839f08 100644
--- a/crypto_kem/sntrup761/avx2/crypto_encode_761xint16.c
+++ b/crypto_kem/sntrup761/avx2/crypto_encode_761xint16.c
@@ -7,7 +7,7 @@ void PQCLEAN_SNTRUP761_AVX2_crypto_encode_761xint16(unsigned char *s, const void
 
     for (i = 0; i < 761; ++i) {
         uint16_t u = *x++;
-        *s++ = u;
-        *s++ = u >> 8;
+        *s++ = (unsigned char) u;
+        *s++ = (unsigned char) (u >> 8);
     }
 }
diff --git a/crypto_kem/sntrup761/avx2/crypto_encode_int16.c b/crypto_kem/sntrup761/avx2/crypto_encode_int16.c
index 378d0667..53b9535d 100644
--- a/crypto_kem/sntrup761/avx2/crypto_encode_int16.c
+++ b/crypto_kem/sntrup761/avx2/crypto_encode_int16.c
@@ -4,6 +4,6 @@
 
 void PQCLEAN_SNTRUP761_AVX2_crypto_encode_int16(unsigned char *s, const void *x) {
     uint16 u = *(const uint16 *) x;
-    s[0] = u;
-    s[1] = u >> 8;
+    s[0] = (unsigned char) u;
+    s[1] = (unsigned char) (u >> 8);
 }
diff --git a/crypto_kem/sntrup761/avx2/crypto_sort_int32.c b/crypto_kem/sntrup761/avx2/crypto_sort_int32.c
index 0f42e458..9de85b51 100644
--- a/crypto_kem/sntrup761/avx2/crypto_sort_int32.c
+++ b/crypto_kem/sntrup761/avx2/crypto_sort_int32.c
@@ -44,7 +44,7 @@ static void minmax_vector(int32 *x, int32 *y, size_t n) {
         int32x8_MINMAX(x0, y0);
         int32x8_store(x + n - 8, x0);
         int32x8_store(y + n - 8, y0);
-        n &= ~7;
+        n &= ~(size_t) 7;
     }
     do {
         int32x8 x0 = int32x8_load(x);
diff --git a/crypto_kem/sntrup761/avx2/crypto_verify_1039.c b/crypto_kem/sntrup761/avx2/crypto_verify_1039.c
index 2bc66d89..e2bc9f1c 100644
--- a/crypto_kem/sntrup761/avx2/crypto_verify_1039.c
+++ b/crypto_kem/sntrup761/avx2/crypto_verify_1039.c
@@ -27,10 +27,10 @@ int PQCLEAN_SNTRUP761_AVX2_crypto_verify_1039(const unsigned char *x, const unsi
     diff |= _mm256_srli_epi32(diff, 16);
     diff |= _mm256_srli_epi64(diff, 32);
 
-    differentbits = _mm256_extract_epi8(diff, 0);
-    differentbits |= _mm256_extract_epi8(diff, 8);
-    differentbits |= _mm256_extract_epi8(diff, 16);
-    differentbits |= _mm256_extract_epi8(diff, 24);
+    differentbits = (unsigned int) _mm256_extract_epi8(diff, 0);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 8);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 16);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 24);
 
     return (int) (1 & ((differentbits - 1) >> 8)) - 1;
 }
diff --git a/crypto_kem/sntrup761/avx2/kem.c b/crypto_kem/sntrup761/avx2/kem.c
index 6eeeb496..4f579ffa 100644
--- a/crypto_kem/sntrup761/avx2/kem.c
+++ b/crypto_kem/sntrup761/avx2/kem.c
@@ -65,7 +65,7 @@ static void Rq_recip3(Fq *out, const small *in) {
 static void Hash(unsigned char *out, const unsigned char *in, int inlen) {
     unsigned char h[64];
     int i;
-    sha512(h, in, inlen);
+    sha512(h, in, (size_t) inlen);
     for (i = 0; i < 32; ++i) {
         out[i] = h[i];
     }
@@ -103,7 +103,7 @@ static void Short_random(small *out) {
     }
     PQCLEAN_SNTRUP761_AVX2_crypto_sort_uint32(L, ppadsort);
     for (i = 0; i < p; ++i) {
-        out[i] = (L[i] & 3) - 1;
+        out[i] = (small) ((L[i] & 3) - 1);
     }
 }
 
@@ -115,7 +115,7 @@ static void Small_random(small *out) {
         L[i] = urandom32();
     }
     for (i = 0; i < p; ++i) {
-        out[i] = (((L[i] & 0x3fffffff) * 3) >> 30) - 1;
+        out[i] = (small) ((((L[i] & 0x3fffffff) * 3) >> 30) - 1);
     }
 }
 
@@ -248,13 +248,13 @@ int PQCLEAN_SNTRUP761_AVX2_crypto_kem_dec(unsigned char *k, const unsigned char
         Hide(x, cnew, r_enc, r, pk, cache);
         mask = crypto_verify_clen(c, cnew);
         for (i = 0; i < Small_bytes; ++i) {
-            r_enc[i + 1] ^= mask & (r_enc[i + 1] ^ rho[i]);
+            r_enc[i + 1] ^= (unsigned char) (mask & (r_enc[i + 1] ^ rho[i]));
         }
         Hash(x + 1, r_enc, 1 + Small_bytes); /* XXX: can instead do cmov on cached hash of rho */
         for (i = 0; i < Ciphertexts_bytes + Confirm_bytes; ++i) {
             x[1 + Hash_bytes + i] = c[i];
         }
-        x[0] = 1 + mask;
+        x[0] = (unsigned char) (1 + mask);
         Hash(k, x, sizeof x);
     }
     return 0;
diff --git a/crypto_kem/sntrup761/clean/Makefile b/crypto_kem/sntrup761/clean/Makefile
index b62759a2..ae82c644 100644
--- a/crypto_kem/sntrup761/clean/Makefile
+++ b/crypto_kem/sntrup761/clean/Makefile
@@ -4,7 +4,7 @@ LIB=libsntrup761_clean.a
 HEADERS=api.h crypto_core_inv3sntrup761.h crypto_core_invsntrup761.h crypto_core_mult3sntrup761.h crypto_core_multsntrup761.h crypto_core_scale3sntrup761.h crypto_core_weightsntrup761.h crypto_core_wforcesntrup761.h crypto_decode_761x1531.h crypto_decode_761x3.h crypto_decode_761x4591.h crypto_decode_761xint16.h crypto_decode_761xint32.h crypto_encode_761x1531.h crypto_encode_761x1531round.h crypto_encode_761x3.h crypto_encode_761x4591.h crypto_encode_761xfreeze3.h crypto_encode_761xint16.h crypto_encode_int16.h crypto_sort_int32.h crypto_sort_uint32.h crypto_stream_aes256ctr.h crypto_verify_1039.h params.h 
 OBJECTS=crypto_core_inv3sntrup761.o crypto_core_invsntrup761.o crypto_core_mult3sntrup761.o crypto_core_multsntrup761.o crypto_core_scale3sntrup761.o crypto_core_weightsntrup761.o crypto_core_wforcesntrup761.o crypto_decode_761x1531.o crypto_decode_761x3.o crypto_decode_761x4591.o crypto_decode_761xint16.o crypto_decode_761xint32.o crypto_encode_761x1531.o crypto_encode_761x1531round.o crypto_encode_761x3.o crypto_encode_761x4591.o crypto_encode_761xfreeze3.o crypto_encode_761xint16.o crypto_encode_int16.o crypto_sort_int32.o crypto_sort_uint32.o crypto_stream_aes256ctr.o crypto_verify_1039.o kem.o 
 
-CFLAGS=-O3 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -std=c99 -I../../../common $(EXTRAFLAGS)
+CFLAGS=-O3 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -Wconversion -std=c99 -I../../../common $(EXTRAFLAGS)
 
 all: $(LIB)
 
diff --git a/crypto_kem/sntrup761/clean/crypto_core_inv3sntrup761.c b/crypto_kem/sntrup761/clean/crypto_core_inv3sntrup761.c
index 9b9af62a..8db3bb2a 100644
--- a/crypto_kem/sntrup761/clean/crypto_core_inv3sntrup761.c
+++ b/crypto_kem/sntrup761/clean/crypto_core_inv3sntrup761.c
@@ -13,16 +13,16 @@
 
 /* return -1 if x!=0; else return 0 */
 static int int16_nonzero_mask(int16 x) {
-    uint16 u = x; /* 0, else 1...65535 */
+    uint16 u = (uint16) x; /* 0, else 1...65535 */
     uint32 v = u; /* 0, else 1...65535 */
     v = -v; /* 0, else 2^32-65535...2^32-1 */
     v >>= 31; /* 0, else 1 */
-    return -v; /* 0, else -1 */
+    return -(int) v; /* 0, else -1 */
 }
 
 /* return -1 if x<0; otherwise return 0 */
 static int int16_negative_mask(int16 x) {
-    uint16 u = x;
+    uint16 u = (uint16) x;
     u >>= 15;
     return -(int) u;
     /* alternative with gcc -fwrapv: */
@@ -36,7 +36,7 @@ typedef int8 small;
 
 /* works for -16384 <= x < 16384 */
 static small F3_freeze(int16 x) {
-    return x - 3 * ((10923 * x + 16384) >> 15);
+    return (small) (x - 3 * ((10923 * x + 16384) >> 15));
 }
 
 /* byte p of output is 0 if recip succeeded; else -1 */
@@ -61,7 +61,7 @@ int PQCLEAN_SNTRUP761_CLEAN_crypto_core_inv3sntrup761(unsigned char *outbytes, c
     f[p - 1] = f[p] = -1;
     for (i = 0; i < p; ++i) {
         small i1 = in[i] & 1;
-        g[p - 1 - i] = i1 - (in[i] & (i1 << 1));
+        g[p - 1 - i] = (small) (i1 - (in[i] & (i1 << 1)));
     }
     g[p] = 0;
 
@@ -74,24 +74,24 @@ int PQCLEAN_SNTRUP761_CLEAN_crypto_core_inv3sntrup761(unsigned char *outbytes, c
         v[0] = 0;
 
         sign = -g[0] * f[0];
-        swap = int16_negative_mask(-delta) & int16_nonzero_mask(g[0]);
+        swap = int16_negative_mask(-(int16) delta) & int16_nonzero_mask(g[0]);
         delta ^= swap & (delta ^ -delta);
         delta += 1;
 
         for (i = 0; i < p + 1; ++i) {
             t = swap & (f[i] ^ g[i]);
-            f[i] ^= t;
-            g[i] ^= t;
+            f[i] ^= (small) t;
+            g[i] ^= (small) t;
             t = swap & (v[i] ^ r[i]);
-            v[i] ^= t;
-            r[i] ^= t;
+            v[i] ^= (small) t;
+            r[i] ^= (small) t;
         }
 
         for (i = 0; i < p + 1; ++i) {
-            g[i] = F3_freeze(g[i] + sign * f[i]);
+            g[i] = F3_freeze((int16) (g[i] + sign * f[i]));
         }
         for (i = 0; i < p + 1; ++i) {
-            r[i] = F3_freeze(r[i] + sign * v[i]);
+            r[i] = F3_freeze((int16) (r[i] + sign * v[i]));
         }
 
         for (i = 0; i < p; ++i) {
@@ -102,9 +102,9 @@ int PQCLEAN_SNTRUP761_CLEAN_crypto_core_inv3sntrup761(unsigned char *outbytes, c
 
     sign = f[0];
     for (i = 0; i < p; ++i) {
-        out[i] = sign * v[p - 1 - i];
+        out[i] = (small) sign * v[p - 1 - i];
     }
 
-    out[p] = int16_nonzero_mask(delta);
+    out[p] = (small) int16_nonzero_mask((int16) delta);
     return 0;
 }
diff --git a/crypto_kem/sntrup761/clean/crypto_core_invsntrup761.c b/crypto_kem/sntrup761/clean/crypto_core_invsntrup761.c
index b496b030..16afe697 100644
--- a/crypto_kem/sntrup761/clean/crypto_core_invsntrup761.c
+++ b/crypto_kem/sntrup761/clean/crypto_core_invsntrup761.c
@@ -13,16 +13,16 @@
 
 /* return -1 if x!=0; else return 0 */
 static int int16_nonzero_mask(int16 x) {
-    uint16 u = x; /* 0, else 1...65535 */
+    uint16 u = (uint16) x; /* 0, else 1...65535 */
     uint32 v = u; /* 0, else 1...65535 */
     v = -v; /* 0, else 2^32-65535...2^32-1 */
     v >>= 31; /* 0, else 1 */
-    return -v; /* 0, else -1 */
+    return -(int) v; /* 0, else -1 */
 }
 
 /* return -1 if x<0; otherwise return 0 */
 static int int16_negative_mask(int16 x) {
-    uint16 u = x;
+    uint16 u = (uint16) x;
     u >>= 15;
     return -(int) u;
     /* alternative with gcc -fwrapv: */
@@ -40,7 +40,7 @@ typedef int16 Fq;
 static Fq Fq_freeze(int32 x) {
     x -= q * ((q18 * x) >> 18);
     x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    return (Fq) x;
 }
 
 static Fq Fq_recip(Fq a1) {
@@ -91,17 +91,17 @@ int PQCLEAN_SNTRUP761_CLEAN_crypto_core_invsntrup761(unsigned char *outbytes, co
         }
         v[0] = 0;
 
-        swap = int16_negative_mask(-delta) & int16_nonzero_mask(g[0]);
+        swap = int16_negative_mask((int16) - delta) & int16_nonzero_mask(g[0]);
         delta ^= swap & (delta ^ -delta);
         delta += 1;
 
         for (i = 0; i < p + 1; ++i) {
             t = swap & (f[i] ^ g[i]);
-            f[i] ^= t;
-            g[i] ^= t;
+            f[i] ^= (Fq) t;
+            g[i] ^= (Fq) t;
             t = swap & (v[i] ^ r[i]);
-            v[i] ^= t;
-            r[i] ^= t;
+            v[i] ^= (Fq) t;
+            r[i] ^= (Fq) t;
         }
 
         f0 = f[0];
@@ -125,6 +125,6 @@ int PQCLEAN_SNTRUP761_CLEAN_crypto_core_invsntrup761(unsigned char *outbytes, co
     }
 
     crypto_encode_pxint16(outbytes, out);
-    outbytes[2 * p] = int16_nonzero_mask(delta);
+    outbytes[2 * p] = (unsigned char) int16_nonzero_mask((int16) delta);
     return 0;
 }
diff --git a/crypto_kem/sntrup761/clean/crypto_core_mult3sntrup761.c b/crypto_kem/sntrup761/clean/crypto_core_mult3sntrup761.c
index 7c32f29e..b25892b4 100644
--- a/crypto_kem/sntrup761/clean/crypto_core_mult3sntrup761.c
+++ b/crypto_kem/sntrup761/clean/crypto_core_mult3sntrup761.c
@@ -8,7 +8,7 @@ typedef int8 small;
 
 /* works for -16384 <= x < 16384 */
 static small F3_freeze(int16 x) {
-    return x - 3 * ((10923 * x + 16384) >> 15);
+    return (small) (x - 3 * ((10923 * x + 16384) >> 15));
 }
 
 int PQCLEAN_SNTRUP761_CLEAN_crypto_core_mult3sntrup761(unsigned char *outbytes, const unsigned char *inbytes, const unsigned char *kbytes) {
@@ -20,27 +20,27 @@ int PQCLEAN_SNTRUP761_CLEAN_crypto_core_mult3sntrup761(unsigned char *outbytes,
     int i, j;
 
     for (i = 0; i < p; ++i) {
-        small fi = inbytes[i];
+        small fi = (small) inbytes[i];
         small fi0 = fi & 1;
-        f[i] = fi0 - (fi & (fi0 << 1));
+        f[i] = (small) (fi0 - (fi & (fi0 << 1)));
     }
     for (i = 0; i < p; ++i) {
-        small gi = kbytes[i];
+        small gi = (small) kbytes[i];
         small gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (small) (gi0 - (gi & (gi0 << 1)));
     }
 
     for (i = 0; i < p; ++i) {
         result = 0;
         for (j = 0; j <= i; ++j) {
-            result += f[j] * g[i - j];
+            result += (small) (f[j] * g[i - j]);
         }
         fg[i] = F3_freeze(result);
     }
     for (i = p; i < p + p - 1; ++i) {
         result = 0;
         for (j = i - p + 1; j < p; ++j) {
-            result += f[j] * g[i - j];
+            result += (small) (f[j] * g[i - j]);
         }
         fg[i] = F3_freeze(result);
     }
diff --git a/crypto_kem/sntrup761/clean/crypto_core_multsntrup761.c b/crypto_kem/sntrup761/clean/crypto_core_multsntrup761.c
index e283456e..0ae23c3c 100644
--- a/crypto_kem/sntrup761/clean/crypto_core_multsntrup761.c
+++ b/crypto_kem/sntrup761/clean/crypto_core_multsntrup761.c
@@ -14,7 +14,7 @@ typedef int16 Fq;
 static Fq Fq_freeze(int32 x) {
     x -= q * ((q18 * x) >> 18);
     x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    return (Fq) x;
 }
 
 int PQCLEAN_SNTRUP761_CLEAN_crypto_core_multsntrup761(unsigned char *outbytes, const unsigned char *inbytes, const unsigned char *kbytes) {
@@ -30,9 +30,9 @@ int PQCLEAN_SNTRUP761_CLEAN_crypto_core_multsntrup761(unsigned char *outbytes, c
     }
 
     for (i = 0; i < p; ++i) {
-        small gi = kbytes[i];
+        small gi = (small) kbytes[i];
         small gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (small) (gi0 - (gi & (gi0 << 1)));
     }
 
     for (i = 0; i < p; ++i) {
diff --git a/crypto_kem/sntrup761/clean/crypto_core_wforcesntrup761.c b/crypto_kem/sntrup761/clean/crypto_core_wforcesntrup761.c
index 806d3111..a60b5405 100644
--- a/crypto_kem/sntrup761/clean/crypto_core_wforcesntrup761.c
+++ b/crypto_kem/sntrup761/clean/crypto_core_wforcesntrup761.c
@@ -12,11 +12,11 @@ typedef int8 small;
 
 /* return -1 if x!=0; else return 0 */
 static int int16_nonzero_mask(int16 x) {
-    uint16 u = x; /* 0, else 1...65535 */
+    uint16 u = (uint16) x; /* 0, else 1...65535 */
     uint32 v = u; /* 0, else 1...65535 */
     v = -v; /* 0, else 2^32-65535...2^32-1 */
     v >>= 31; /* 0, else 1 */
-    return -v; /* 0, else -1 */
+    return -(int) v; /* 0, else -1 */
 }
 
 /* 0 if Weightw_is(r), else -1 */
@@ -27,7 +27,7 @@ static int Weightw_mask(const small *r) {
     for (i = 0; i < p; ++i) {
         weight += r[i] & 1;
     }
-    return int16_nonzero_mask(weight - w);
+    return int16_nonzero_mask((int16) (weight - w));
 }
 
 /* out = in if bottom bits of in have weight w */
@@ -39,10 +39,10 @@ int PQCLEAN_SNTRUP761_CLEAN_crypto_core_wforcesntrup761(unsigned char *outbytes,
 
     mask = Weightw_mask(in); /* 0 if weight w, else -1 */
     for (i = 0; i < w; ++i) {
-        out[i] = ((in[i] ^ 1) & ~mask) ^ 1;
+        out[i] = (small) (((in[i] ^ 1) & ~mask) ^ 1);
     }
     for (i = w; i < p; ++i) {
-        out[i] = in[i] & ~mask;
+        out[i] = (small) (in[i] & ~mask);
     }
     return 0;
 }
diff --git a/crypto_kem/sntrup761/clean/crypto_decode_761x1531.c b/crypto_kem/sntrup761/clean/crypto_decode_761x1531.c
index d19d7402..7d5f926b 100644
--- a/crypto_kem/sntrup761/clean/crypto_decode_761x1531.c
+++ b/crypto_kem/sntrup761/clean/crypto_decode_761x1531.c
@@ -30,7 +30,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
 
     *q = 0;
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 2^31 qpart <= xv <= 2^31 qpart + 2^31-1 */
     /* 2^31 qpart m <= xvm <= 2^31 qpart m + (2^31-1)m */
     /* 2^31 qpart m <= 2^31 x <= 2^31 qpart m + (2^31-1)m + x(m-1) */
@@ -42,7 +42,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += qpart;
     /* x <= 49146 */
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 0 <= newx <= (1-1/2^31)m + x(m-1)/2^31 */
     /* 0 <= newx <= m + 49146(2^14-1)/2^31 */
     /* 0 <= newx <= m + 0.4 */
@@ -59,7 +59,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += mask;
     /* x < m */
 
-    *r = x;
+    *r = (uint16) x;
 }
 
 static uint16 uint32_mod_uint14(uint32 x, uint16 m) {
@@ -81,14 +81,14 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x1531(void *v, const unsigned char
     r1 = (r1 << 8) | *--s;
     r1 = (r1 << 8) | *--s;
     r1 = uint32_mod_uint14(r1, 3475); /* needed only for invalid inputs */
-    R10[0] = r1;
+    R10[0] = (uint16) r1;
 
     r2 = R10[0];
     r2 = (r2 << 8) | *--s;
     uint32_divmod_uint14(&r1, &r0, r2, 593);
     R9[0] = r0;
     r1 = uint32_mod_uint14(r1, 1500); /* needed only for invalid inputs */
-    R9[1] = r1;
+    R9[1] = (uint16) r1;
 
     R8[2] = R9[1];
     r2 = R9[0];
@@ -97,21 +97,21 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x1531(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 6232);
     R8[0] = r0;
     r1 = uint32_mod_uint14(r1, 6232); /* needed only for invalid inputs */
-    R8[1] = r1;
+    R8[1] = (uint16) r1;
 
     r2 = R8[2];
     r2 = (r2 << 8) | *--s;
     uint32_divmod_uint14(&r1, &r0, r2, 1263);
     R7[4] = r0;
     r1 = uint32_mod_uint14(r1, 304); /* needed only for invalid inputs */
-    R7[5] = r1;
+    R7[5] = (uint16) r1;
     for (i = 1; i >= 0; --i) {
         r2 = R8[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 1263);
         R7[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 1263); /* needed only for invalid inputs */
-        R7[2 * i + 1] = r1;
+        R7[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R7[5];
@@ -120,7 +120,7 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x1531(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 9097);
     R6[10] = r0;
     r1 = uint32_mod_uint14(r1, 2188); /* needed only for invalid inputs */
-    R6[11] = r1;
+    R6[11] = (uint16) r1;
     for (i = 4; i >= 0; --i) {
         r2 = R7[i];
         r2 = (r2 << 8) | *--s;
@@ -128,7 +128,7 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x1531(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 9097);
         R6[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 9097); /* needed only for invalid inputs */
-        R6[2 * i + 1] = r1;
+        R6[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R6[11];
@@ -136,14 +136,14 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x1531(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 1526);
     R5[22] = r0;
     r1 = uint32_mod_uint14(r1, 367); /* needed only for invalid inputs */
-    R5[23] = r1;
+    R5[23] = (uint16) r1;
     for (i = 10; i >= 0; --i) {
         r2 = R6[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 1526);
         R5[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 1526); /* needed only for invalid inputs */
-        R5[2 * i + 1] = r1;
+        R5[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R5[23];
@@ -151,14 +151,14 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x1531(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 625);
     R4[46] = r0;
     r1 = uint32_mod_uint14(r1, 150); /* needed only for invalid inputs */
-    R4[47] = r1;
+    R4[47] = (uint16) r1;
     for (i = 22; i >= 0; --i) {
         r2 = R5[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 625);
         R4[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 625); /* needed only for invalid inputs */
-        R4[2 * i + 1] = r1;
+        R4[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R4[47];
@@ -167,7 +167,7 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x1531(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 6400);
     R3[94] = r0;
     r1 = uint32_mod_uint14(r1, 1531); /* needed only for invalid inputs */
-    R3[95] = r1;
+    R3[95] = (uint16) r1;
     for (i = 46; i >= 0; --i) {
         r2 = R4[i];
         r2 = (r2 << 8) | *--s;
@@ -175,7 +175,7 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x1531(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 6400);
         R3[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 6400); /* needed only for invalid inputs */
-        R3[2 * i + 1] = r1;
+        R3[2 * i + 1] = (uint16) r1;
     }
 
     R2[190] = R3[95];
@@ -185,7 +185,7 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x1531(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 1280);
         R2[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 1280); /* needed only for invalid inputs */
-        R2[2 * i + 1] = r1;
+        R2[2 * i + 1] = (uint16) r1;
     }
 
     R1[380] = R2[190];
@@ -196,16 +196,16 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x1531(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 9157);
         R1[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 9157); /* needed only for invalid inputs */
-        R1[2 * i + 1] = r1;
+        R1[2 * i + 1] = (uint16) r1;
     }
 
-    R0[760] = 3 * R1[380] - 2295;
+    R0[760] = (int16) (3 * R1[380] - 2295);
     for (i = 379; i >= 0; --i) {
         r2 = R1[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 1531);
-        R0[2 * i] = 3 * r0 - 2295;
+        R0[2 * i] = (int16) (3 * r0 - 2295);
         r1 = uint32_mod_uint14(r1, 1531); /* needed only for invalid inputs */
-        R0[2 * i + 1] = 3 * r1 - 2295;
+        R0[2 * i + 1] = (int16) (3 * r1 - 2295);
     }
 }
diff --git a/crypto_kem/sntrup761/clean/crypto_decode_761x4591.c b/crypto_kem/sntrup761/clean/crypto_decode_761x4591.c
index 630c11fe..0054517b 100644
--- a/crypto_kem/sntrup761/clean/crypto_decode_761x4591.c
+++ b/crypto_kem/sntrup761/clean/crypto_decode_761x4591.c
@@ -30,7 +30,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
 
     *q = 0;
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 2^31 qpart <= xv <= 2^31 qpart + 2^31-1 */
     /* 2^31 qpart m <= xvm <= 2^31 qpart m + (2^31-1)m */
     /* 2^31 qpart m <= 2^31 x <= 2^31 qpart m + (2^31-1)m + x(m-1) */
@@ -42,7 +42,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += qpart;
     /* x <= 49146 */
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 0 <= newx <= (1-1/2^31)m + x(m-1)/2^31 */
     /* 0 <= newx <= m + 49146(2^14-1)/2^31 */
     /* 0 <= newx <= m + 0.4 */
@@ -59,7 +59,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += mask;
     /* x < m */
 
-    *r = x;
+    *r = (uint16) x;
 }
 
 static uint16 uint32_mod_uint14(uint32 x, uint16 m) {
@@ -81,7 +81,7 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x4591(void *v, const unsigned char
     r1 = (r1 << 8) | *--s;
     r1 = (r1 << 8) | *--s;
     r1 = uint32_mod_uint14(r1, 1608); /* needed only for invalid inputs */
-    R10[0] = r1;
+    R10[0] = (uint16) r1;
 
     r2 = R10[0];
     r2 = (r2 << 8) | *--s;
@@ -89,7 +89,7 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x4591(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 9470);
     R9[0] = r0;
     r1 = uint32_mod_uint14(r1, 11127); /* needed only for invalid inputs */
-    R9[1] = r1;
+    R9[1] = (uint16) r1;
 
     R8[2] = R9[1];
     r2 = R9[0];
@@ -97,14 +97,14 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x4591(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 1557);
     R8[0] = r0;
     r1 = uint32_mod_uint14(r1, 1557); /* needed only for invalid inputs */
-    R8[1] = r1;
+    R8[1] = (uint16) r1;
 
     r2 = R8[2];
     r2 = (r2 << 8) | *--s;
     uint32_divmod_uint14(&r1, &r0, r2, 10101);
     R7[4] = r0;
     r1 = uint32_mod_uint14(r1, 282); /* needed only for invalid inputs */
-    R7[5] = r1;
+    R7[5] = (uint16) r1;
     for (i = 1; i >= 0; --i) {
         r2 = R8[i];
         r2 = (r2 << 8) | *--s;
@@ -112,7 +112,7 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x4591(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 10101);
         R7[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 10101); /* needed only for invalid inputs */
-        R7[2 * i + 1] = r1;
+        R7[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R7[5];
@@ -121,14 +121,14 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x4591(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 1608);
     R6[10] = r0;
     r1 = uint32_mod_uint14(r1, 11468); /* needed only for invalid inputs */
-    R6[11] = r1;
+    R6[11] = (uint16) r1;
     for (i = 4; i >= 0; --i) {
         r2 = R7[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 1608);
         R6[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 1608); /* needed only for invalid inputs */
-        R6[2 * i + 1] = r1;
+        R6[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R6[11];
@@ -136,7 +136,7 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x4591(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 10265);
     R5[22] = r0;
     r1 = uint32_mod_uint14(r1, 286); /* needed only for invalid inputs */
-    R5[23] = r1;
+    R5[23] = (uint16) r1;
     for (i = 10; i >= 0; --i) {
         r2 = R6[i];
         r2 = (r2 << 8) | *--s;
@@ -144,7 +144,7 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x4591(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 10265);
         R5[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 10265); /* needed only for invalid inputs */
-        R5[2 * i + 1] = r1;
+        R5[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R5[23];
@@ -153,14 +153,14 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x4591(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 1621);
     R4[46] = r0;
     r1 = uint32_mod_uint14(r1, 11550); /* needed only for invalid inputs */
-    R4[47] = r1;
+    R4[47] = (uint16) r1;
     for (i = 22; i >= 0; --i) {
         r2 = R5[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 1621);
         R4[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 1621); /* needed only for invalid inputs */
-        R4[2 * i + 1] = r1;
+        R4[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R4[47];
@@ -168,14 +168,14 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x4591(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 644);
     R3[94] = r0;
     r1 = uint32_mod_uint14(r1, 4591); /* needed only for invalid inputs */
-    R3[95] = r1;
+    R3[95] = (uint16) r1;
     for (i = 46; i >= 0; --i) {
         r2 = R4[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 644);
         R3[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 644); /* needed only for invalid inputs */
-        R3[2 * i + 1] = r1;
+        R3[2 * i + 1] = (uint16) r1;
     }
 
     R2[190] = R3[95];
@@ -185,7 +185,7 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x4591(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 406);
         R2[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 406); /* needed only for invalid inputs */
-        R2[2 * i + 1] = r1;
+        R2[2 * i + 1] = (uint16) r1;
     }
 
     R1[380] = R2[190];
@@ -195,17 +195,17 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761x4591(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 322);
         R1[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 322); /* needed only for invalid inputs */
-        R1[2 * i + 1] = r1;
+        R1[2 * i + 1] = (uint16) r1;
     }
 
-    R0[760] = R1[380] - 2295;
+    R0[760] = (int16) (R1[380] - 2295);
     for (i = 379; i >= 0; --i) {
         r2 = R1[i];
         r2 = (r2 << 8) | *--s;
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 4591);
-        R0[2 * i] = r0 - 2295;
+        R0[2 * i] = (int16) (r0 - 2295);
         r1 = uint32_mod_uint14(r1, 4591); /* needed only for invalid inputs */
-        R0[2 * i + 1] = r1 - 2295;
+        R0[2 * i + 1] = (int16) (r1 - 2295);
     }
 }
diff --git a/crypto_kem/sntrup761/clean/crypto_decode_761xint16.c b/crypto_kem/sntrup761/clean/crypto_decode_761xint16.c
index 7678d872..5d60473c 100644
--- a/crypto_kem/sntrup761/clean/crypto_decode_761xint16.c
+++ b/crypto_kem/sntrup761/clean/crypto_decode_761xint16.c
@@ -8,8 +8,7 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_decode_761xint16(void *v, const unsigned cha
     for (i = 0; i < 761; ++i) {
         uint16_t u0 = s[0];
         uint16_t u1 = s[1];
-        u1 <<= 8;
-        *x = u0 | u1;
+        *x = (uint16_t) (u0 | (u1 << 8));
         x += 1;
         s += 2;
     }
diff --git a/crypto_kem/sntrup761/clean/crypto_encode_761x1531.c b/crypto_kem/sntrup761/clean/crypto_encode_761x1531.c
index 17db0eef..3ef8b3f1 100644
--- a/crypto_kem/sntrup761/clean/crypto_encode_761x1531.c
+++ b/crypto_kem/sntrup761/clean/crypto_encode_761x1531.c
@@ -15,24 +15,24 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_encode_761x1531(unsigned char *out, const vo
     uint32 r2;
 
     for (i = 0; i < 380; ++i) {
-        r0 = (((R0[2 * i] + 2295) & 16383) * 10923) >> 15;
-        r1 = (((R0[2 * i + 1] + 2295) & 16383) * 10923) >> 15;
+        r0 = (uint16) ((((R0[2 * i] + 2295) & 16383) * 10923) >> 15);
+        r1 = (uint16) ((((R0[2 * i + 1] + 2295) & 16383) * 10923) >> 15);
         r2 = r0 + r1 * (uint32)1531;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
-    R[380] = (((R0[760] + 2295) & 16383) * 10923) >> 15;
+    R[380] = (uint16) ((((R0[760] + 2295) & 16383) * 10923) >> 15);
 
     for (i = 0; i < 190; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)9157;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[190] = R[380];
 
@@ -40,9 +40,9 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_encode_761x1531(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1280;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[95] = R[190];
 
@@ -50,70 +50,70 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_encode_761x1531(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)6400;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 24; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)625;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 12; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1526;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 6; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)9097;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 3; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1263;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)6232;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)593;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/sntrup761/clean/crypto_encode_761x1531round.c b/crypto_kem/sntrup761/clean/crypto_encode_761x1531round.c
index 6b10ccb4..6906d3e2 100644
--- a/crypto_kem/sntrup761/clean/crypto_encode_761x1531round.c
+++ b/crypto_kem/sntrup761/clean/crypto_encode_761x1531round.c
@@ -11,7 +11,7 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_encode_761x1531round(unsigned char *out, con
     int i;
 
     for (i = 0; i < p; ++i) {
-        x[i] = 3 * ((10923 * a[i] + 16384) >> 15);
+        x[i] = (int16) (3 * ((10923 * a[i] + 16384) >> 15));
     }
     PQCLEAN_SNTRUP761_CLEAN_crypto_encode_761x1531(out, x);
 }
diff --git a/crypto_kem/sntrup761/clean/crypto_encode_761x3.c b/crypto_kem/sntrup761/clean/crypto_encode_761x3.c
index 54deace0..32d00f3b 100644
--- a/crypto_kem/sntrup761/clean/crypto_encode_761x3.c
+++ b/crypto_kem/sntrup761/clean/crypto_encode_761x3.c
@@ -11,9 +11,9 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_encode_761x3(unsigned char *s, const void *v
 
     for (i = 0; i < p / 4; ++i) {
         x = *f++ + 1;
-        x += (*f++ + 1) << 2;
-        x += (*f++ + 1) << 4;
-        x += (*f++ + 1) << 6;
+        x += (uint8) ((*f++ + 1) << 2);
+        x += (uint8) ((*f++ + 1) << 4);
+        x += (uint8) ((*f++ + 1) << 6);
         *s++ = x;
     }
     x = *f++ + 1;
diff --git a/crypto_kem/sntrup761/clean/crypto_encode_761x4591.c b/crypto_kem/sntrup761/clean/crypto_encode_761x4591.c
index c09514c2..1f82a69b 100644
--- a/crypto_kem/sntrup761/clean/crypto_encode_761x4591.c
+++ b/crypto_kem/sntrup761/clean/crypto_encode_761x4591.c
@@ -18,11 +18,11 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_encode_761x4591(unsigned char *out, const vo
         r0 = (R0[2 * i] + 2295) & 16383;
         r1 = (R0[2 * i + 1] + 2295) & 16383;
         r2 = r0 + r1 * (uint32)4591;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[380] = (R0[760] + 2295) & 16383;
 
@@ -30,9 +30,9 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_encode_761x4591(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)322;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[190] = R[380];
 
@@ -40,9 +40,9 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_encode_761x4591(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)406;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[95] = R[190];
 
@@ -50,98 +50,98 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_encode_761x4591(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)644;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 23; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1621;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[46];
     r1 = R[47];
     r2 = r0 + r1 * (uint32)1621;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[23] = r2;
+    R[23] = (uint16) r2;
 
     for (i = 0; i < 11; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)10265;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[22];
     r1 = R[23];
     r2 = r0 + r1 * (uint32)10265;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[11] = r2;
+    R[11] = (uint16) r2;
 
     for (i = 0; i < 5; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1608;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[10];
     r1 = R[11];
     r2 = r0 + r1 * (uint32)1608;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[5] = r2;
+    R[5] = (uint16) r2;
 
     for (i = 0; i < 2; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)10101;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[4];
     r1 = R[5];
     r2 = r0 + r1 * (uint32)10101;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[2] = r2;
+    R[2] = (uint16) r2;
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)1557;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     R[1] = R[2];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)9470;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/sntrup761/clean/crypto_encode_761xfreeze3.c b/crypto_kem/sntrup761/clean/crypto_encode_761xfreeze3.c
index d2b10e3e..f196e033 100644
--- a/crypto_kem/sntrup761/clean/crypto_encode_761xfreeze3.c
+++ b/crypto_kem/sntrup761/clean/crypto_encode_761xfreeze3.c
@@ -12,7 +12,7 @@
 /* and F3_freeze(x) is in {-2,-1,0,1,2} */
 
 static inline unsigned char F3_freeze(int16 x) {
-    return x - 3 * ((10923 * x + 16384) >> 15);
+    return (unsigned char) (x - 3 * ((10923 * x + 16384) >> 15));
 }
 
 void PQCLEAN_SNTRUP761_CLEAN_crypto_encode_761xfreeze3(unsigned char *s, const void *v) {
diff --git a/crypto_kem/sntrup761/clean/crypto_encode_761xint16.c b/crypto_kem/sntrup761/clean/crypto_encode_761xint16.c
index 02384178..c5dcf16a 100644
--- a/crypto_kem/sntrup761/clean/crypto_encode_761xint16.c
+++ b/crypto_kem/sntrup761/clean/crypto_encode_761xint16.c
@@ -7,7 +7,7 @@ void PQCLEAN_SNTRUP761_CLEAN_crypto_encode_761xint16(unsigned char *s, const voi
 
     for (i = 0; i < 761; ++i) {
         uint16_t u = *x++;
-        *s++ = u;
-        *s++ = u >> 8;
+        *s++ = (unsigned char) u;
+        *s++ = (unsigned char) (u >> 8);
     }
 }
diff --git a/crypto_kem/sntrup761/clean/crypto_encode_int16.c b/crypto_kem/sntrup761/clean/crypto_encode_int16.c
index 074814aa..78b0d682 100644
--- a/crypto_kem/sntrup761/clean/crypto_encode_int16.c
+++ b/crypto_kem/sntrup761/clean/crypto_encode_int16.c
@@ -4,6 +4,6 @@
 
 void PQCLEAN_SNTRUP761_CLEAN_crypto_encode_int16(unsigned char *s, const void *x) {
     uint16 u = *(const uint16 *) x;
-    s[0] = u;
-    s[1] = u >> 8;
+    s[0] = (unsigned char) u;
+    s[1] = (unsigned char) (u >> 8);
 }
diff --git a/crypto_kem/sntrup761/clean/kem.c b/crypto_kem/sntrup761/clean/kem.c
index fd9f1f63..87175305 100644
--- a/crypto_kem/sntrup761/clean/kem.c
+++ b/crypto_kem/sntrup761/clean/kem.c
@@ -65,7 +65,7 @@ static void Rq_recip3(Fq *out, const small *in) {
 static void Hash(unsigned char *out, const unsigned char *in, int inlen) {
     unsigned char h[64];
     int i;
-    sha512(h, in, inlen);
+    sha512(h, in, (size_t) inlen);
     for (i = 0; i < 32; ++i) {
         out[i] = h[i];
     }
@@ -103,7 +103,7 @@ static void Short_random(small *out) {
     }
     PQCLEAN_SNTRUP761_CLEAN_crypto_sort_uint32(L, ppadsort);
     for (i = 0; i < p; ++i) {
-        out[i] = (L[i] & 3) - 1;
+        out[i] = (small) ((L[i] & 3) - 1);
     }
 }
 
@@ -115,7 +115,7 @@ static void Small_random(small *out) {
         L[i] = urandom32();
     }
     for (i = 0; i < p; ++i) {
-        out[i] = (((L[i] & 0x3fffffff) * 3) >> 30) - 1;
+        out[i] = (small) ((((L[i] & 0x3fffffff) * 3) >> 30) - 1);
     }
 }
 
@@ -248,13 +248,13 @@ int PQCLEAN_SNTRUP761_CLEAN_crypto_kem_dec(unsigned char *k, const unsigned char
         Hide(x, cnew, r_enc, r, pk, cache);
         mask = crypto_verify_clen(c, cnew);
         for (i = 0; i < Small_bytes; ++i) {
-            r_enc[i + 1] ^= mask & (r_enc[i + 1] ^ rho[i]);
+            r_enc[i + 1] ^= (unsigned char) (mask & (r_enc[i + 1] ^ rho[i]));
         }
         Hash(x + 1, r_enc, 1 + Small_bytes); /* XXX: can instead do cmov on cached hash of rho */
         for (i = 0; i < Ciphertexts_bytes + Confirm_bytes; ++i) {
             x[1 + Hash_bytes + i] = c[i];
         }
-        x[0] = 1 + mask;
+        x[0] = (unsigned char) (1 + mask);
         Hash(k, x, sizeof x);
     }
     return 0;
diff --git a/crypto_kem/sntrup857/avx2/Makefile b/crypto_kem/sntrup857/avx2/Makefile
index 58d4d010..e49c52a1 100644
--- a/crypto_kem/sntrup857/avx2/Makefile
+++ b/crypto_kem/sntrup857/avx2/Makefile
@@ -4,7 +4,7 @@ LIB=libsntrup857_avx2.a
 HEADERS=api.h crypto_core_inv3sntrup857.h crypto_core_invsntrup857.h crypto_core_mult3sntrup857.h crypto_core_multsntrup857.h crypto_core_multsntrup857_ntt.h crypto_core_scale3sntrup857.h crypto_core_weightsntrup857.h crypto_core_wforcesntrup857.h crypto_decode_857x1723.h crypto_decode_857x3.h crypto_decode_857x5167.h crypto_decode_857xint16.h crypto_decode_857xint32.h crypto_decode_int16.h crypto_encode_857x1723.h crypto_encode_857x1723round.h crypto_encode_857x3.h crypto_encode_857x5167.h crypto_encode_857xfreeze3.h crypto_encode_857xint16.h crypto_encode_int16.h crypto_sort_int32.h crypto_sort_uint32.h crypto_stream_aes256ctr.h crypto_verify_1184.h params.h 
 OBJECTS=crypto_core_inv3sntrup857.o crypto_core_invsntrup857.o crypto_core_mult3sntrup857.o crypto_core_multsntrup857.o crypto_core_multsntrup857_ntt.o crypto_core_scale3sntrup857.o crypto_core_weightsntrup857.o crypto_core_wforcesntrup857.o crypto_decode_857x1723.o crypto_decode_857x3.o crypto_decode_857x5167.o crypto_decode_857xint16.o crypto_decode_857xint32.o crypto_decode_int16.o crypto_encode_857x1723.o crypto_encode_857x1723round.o crypto_encode_857x3.o crypto_encode_857x5167.o crypto_encode_857xfreeze3.o crypto_encode_857xint16.o crypto_encode_int16.o crypto_sort_int32.o crypto_sort_uint32.o crypto_stream_aes256ctr.o crypto_verify_1184.o kem.o 
 
-CFLAGS=-O3 -mavx2 -mbmi2 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -std=c99 -I../../../common $(EXTRAFLAGS)
+CFLAGS=-O3 -mavx2 -mbmi2 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -Wconversion -std=c99 -I../../../common $(EXTRAFLAGS)
 
 all: $(LIB)
 
diff --git a/crypto_kem/sntrup857/avx2/crypto_core_inv3sntrup857.c b/crypto_kem/sntrup857/avx2/crypto_core_inv3sntrup857.c
index 70a67231..f359e6c6 100644
--- a/crypto_kem/sntrup857/avx2/crypto_core_inv3sntrup857.c
+++ b/crypto_kem/sntrup857/avx2/crypto_core_inv3sntrup857.c
@@ -179,7 +179,7 @@ static void vec256_final(small *out, const vec256 *V0, const vec256 *V1) {
     vec256_tobits(V1, v1);
 
     for (i = 0; i < ppad; ++i) {
-        v[i] = v0[i] + 2 * v1[i] - 4 * (v0[i] & v1[i]);
+        v[i] = (small) (v0[i] + 2 * v1[i] - 4 * (v0[i] & v1[i]));
     }
 
     for (i = 0; i < ppad; ++i) {
@@ -252,11 +252,11 @@ static inline int vec256_bit0mask(vec256 *f) {
 static inline void vec256_divx_1(vec256 *f) {
     vec256 f0 = f[0];
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
 
     low0 = low0 >> 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
 
     f[0] = _mm256_permute4x64_epi64(f0, 0x39);
 }
@@ -265,14 +265,14 @@ static inline void vec256_divx_2(vec256 *f) {
     vec256 f0 = f[0];
     vec256 f1 = f[1];
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
-    unsigned long long low1 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low1 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
 
     low0 = (low0 >> 1) | (low1 << 63);
     low1 = low1 >> 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
-    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, low1), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
+    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, (long long) low1), 0x3);
 
     f[0] = _mm256_permute4x64_epi64(f0, 0x39);
     f[1] = _mm256_permute4x64_epi64(f1, 0x39);
@@ -283,17 +283,17 @@ static inline void vec256_divx_3(vec256 *f) {
     vec256 f1 = f[1];
     vec256 f2 = f[2];
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
-    unsigned long long low1 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
-    unsigned long long low2 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low1 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
+    unsigned long long low2 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
 
     low0 = (low0 >> 1) | (low1 << 63);
     low1 = (low1 >> 1) | (low2 << 63);
     low2 = low2 >> 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
-    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, low1), 0x3);
-    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, low2), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
+    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, (long long) low1), 0x3);
+    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, (long long) low2), 0x3);
 
     f[0] = _mm256_permute4x64_epi64(f0, 0x39);
     f[1] = _mm256_permute4x64_epi64(f1, 0x39);
@@ -306,20 +306,20 @@ static inline void vec256_divx_4(vec256 *f) {
     vec256 f2 = f[2];
     vec256 f3 = f[3];
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
-    unsigned long long low1 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
-    unsigned long long low2 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
-    unsigned long long low3 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f3));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low1 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
+    unsigned long long low2 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
+    unsigned long long low3 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f3));
 
     low0 = (low0 >> 1) | (low1 << 63);
     low1 = (low1 >> 1) | (low2 << 63);
     low2 = (low2 >> 1) | (low3 << 63);
     low3 = low3 >> 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
-    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, low1), 0x3);
-    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, low2), 0x3);
-    f3 = _mm256_blend_epi32(f3, _mm256_set_epi64x(0, 0, 0, low3), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
+    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, (long long) low1), 0x3);
+    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, (long long) low2), 0x3);
+    f3 = _mm256_blend_epi32(f3, _mm256_set_epi64x(0, 0, 0, (long long) low3), 0x3);
 
     f[0] = _mm256_permute4x64_epi64(f0, 0x39);
     f[1] = _mm256_permute4x64_epi64(f1, 0x39);
@@ -330,11 +330,11 @@ static inline void vec256_divx_4(vec256 *f) {
 static inline void vec256_timesx_1(vec256 *f) {
     vec256 f0 = _mm256_permute4x64_epi64(f[0], 0x93);
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
 
     low0 = low0 << 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
 
     f[0] = f0;
 }
@@ -343,14 +343,14 @@ static inline void vec256_timesx_2(vec256 *f) {
     vec256 f0 = _mm256_permute4x64_epi64(f[0], 0x93);
     vec256 f1 = _mm256_permute4x64_epi64(f[1], 0x93);
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
-    unsigned long long low1 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low1 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
 
     low1 = (low1 << 1) | (low0 >> 63);
     low0 = low0 << 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
-    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, low1), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
+    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, (long long) low1), 0x3);
 
     f[0] = f0;
     f[1] = f1;
@@ -363,7 +363,7 @@ static inline void vec256_timesx_3(vec256 *f) {
 
     unsigned long long low0 = *(unsigned long long *) &f0;
     unsigned long long low1 = *(unsigned long long *) &f1;
-    unsigned long long low2 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
+    unsigned long long low2 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
 
     low2 = (low2 << 1) | (low1 >> 63);
     low1 = (low1 << 1) | (low0 >> 63);
@@ -371,7 +371,7 @@ static inline void vec256_timesx_3(vec256 *f) {
 
     *(unsigned long long *) &f0 = low0;
     *(unsigned long long *) &f1 = low1;
-    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, low2), 0x3);
+    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, (long long) low2), 0x3);
 
     f[0] = f0;
     f[1] = f1;
@@ -384,20 +384,20 @@ static inline void vec256_timesx_4(vec256 *f) {
     vec256 f2 = _mm256_permute4x64_epi64(f[2], 0x93);
     vec256 f3 = _mm256_permute4x64_epi64(f[3], 0x93);
 
-    unsigned long long low0 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
-    unsigned long long low1 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
-    unsigned long long low2 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
-    unsigned long long low3 = _mm_cvtsi128_si64(_mm256_castsi256_si128(f3));
+    unsigned long long low0 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f0));
+    unsigned long long low1 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f1));
+    unsigned long long low2 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f2));
+    unsigned long long low3 = (unsigned long long) _mm_cvtsi128_si64(_mm256_castsi256_si128(f3));
 
     low3 = (low3 << 1) | (low2 >> 63);
     low2 = (low2 << 1) | (low1 >> 63);
     low1 = (low1 << 1) | (low0 >> 63);
     low0 = low0 << 1;
 
-    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, low0), 0x3);
-    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, low1), 0x3);
-    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, low2), 0x3);
-    f3 = _mm256_blend_epi32(f3, _mm256_set_epi64x(0, 0, 0, low3), 0x3);
+    f0 = _mm256_blend_epi32(f0, _mm256_set_epi64x(0, 0, 0, (long long) low0), 0x3);
+    f1 = _mm256_blend_epi32(f1, _mm256_set_epi64x(0, 0, 0, (long long) low1), 0x3);
+    f2 = _mm256_blend_epi32(f2, _mm256_set_epi64x(0, 0, 0, (long long) low2), 0x3);
+    f3 = _mm256_blend_epi32(f3, _mm256_set_epi64x(0, 0, 0, (long long) low3), 0x3);
 
     f[0] = f0;
     f[1] = f1;
@@ -653,6 +653,6 @@ int PQCLEAN_SNTRUP857_AVX2_crypto_core_inv3sntrup857(unsigned char *outbytes, co
     vec256_scale(V0, V1, c0vec, c1vec);
 
     vec256_final(out, V0, V1);
-    out[p] = negative_mask(minusdelta);
+    out[p] = (small) negative_mask(minusdelta);
     return 0;
 }
diff --git a/crypto_kem/sntrup857/avx2/crypto_core_invsntrup857.c b/crypto_kem/sntrup857/avx2/crypto_core_invsntrup857.c
index 764c10ed..4ca429cd 100644
--- a/crypto_kem/sntrup857/avx2/crypto_core_invsntrup857.c
+++ b/crypto_kem/sntrup857/avx2/crypto_core_invsntrup857.c
@@ -14,11 +14,11 @@
 
 /* return -1 if x!=0; else return 0 */
 static int int16_nonzero_mask(int16 x) {
-    uint16 u = x; /* 0, else 1...65535 */
+    uint16 u = (uint16) x; /* 0, else 1...65535 */
     uint32 v = u; /* 0, else 1...65535 */
     v = -v; /* 0, else 2^32-65535...2^32-1 */
     v >>= 31; /* 0, else 1 */
-    return -v; /* 0, else -1 */
+    return -(int) v; /* 0, else -1 */
 }
 
 /* return -1 if x<0; otherwise return 0 */
@@ -37,7 +37,7 @@ typedef int16 Fq;
 static Fq Fq_freeze(int32 x) {
     x -= q * ((q18 * x) >> 18);
     x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    return (Fq) x;
 }
 
 /* nonnegative e */
@@ -158,13 +158,13 @@ int PQCLEAN_SNTRUP857_AVX2_crypto_core_invsntrup857(unsigned char *outbytes, con
         f0 = f[0];
 
         minusdelta = -delta;
-        swap = int16_negative_mask(minusdelta) & int16_nonzero_mask(g0);
+        swap = int16_negative_mask((int16) minusdelta) & int16_nonzero_mask(g0);
         delta ^= swap & (delta ^ minusdelta);
         delta += 1;
 
         fgflip = swap & (f0 ^ g0);
-        f0 ^= fgflip;
-        g0 ^= fgflip;
+        f0 ^= (Fq) fgflip;
+        g0 ^= (Fq) fgflip;
 
         f[0] = f0;
 
@@ -177,13 +177,13 @@ int PQCLEAN_SNTRUP857_AVX2_crypto_core_invsntrup857(unsigned char *outbytes, con
         f0 = f[0];
 
         minusdelta = -delta;
-        swap = int16_negative_mask(minusdelta) & int16_nonzero_mask(g0);
+        swap = int16_negative_mask((int16) minusdelta) & int16_nonzero_mask(g0);
         delta ^= swap & (delta ^ minusdelta);
         delta += 1;
 
         fgflip = swap & (f0 ^ g0);
-        f0 ^= fgflip;
-        g0 ^= fgflip;
+        f0 ^= (Fq) fgflip;
+        g0 ^= (Fq) fgflip;
 
         f[0] = f0;
 
@@ -197,6 +197,6 @@ int PQCLEAN_SNTRUP857_AVX2_crypto_core_invsntrup857(unsigned char *outbytes, con
     }
 
     crypto_encode_pxint16(outbytes, out);
-    outbytes[2 * p] = int16_nonzero_mask(delta);
+    outbytes[2 * p] = (unsigned char) int16_nonzero_mask((int16) delta);
     return 0;
 }
diff --git a/crypto_kem/sntrup857/avx2/crypto_core_mult3sntrup857.c b/crypto_kem/sntrup857/avx2/crypto_core_mult3sntrup857.c
index dd4b9fa4..c39cc70d 100644
--- a/crypto_kem/sntrup857/avx2/crypto_core_mult3sntrup857.c
+++ b/crypto_kem/sntrup857/avx2/crypto_core_mult3sntrup857.c
@@ -266,14 +266,14 @@ int PQCLEAN_SNTRUP857_AVX2_crypto_core_mult3sntrup857(unsigned char *outbytes, c
     }
 
     for (i = 0; i < p; ++i) {
-        int8 fi = inbytes[i];
+        int8 fi = (int8) inbytes[i];
         int8 fi0 = fi & 1;
-        f[i] = fi0 - (fi & (fi0 << 1));
+        f[i] = (int16) (fi0 - (fi & (fi0 << 1)));
     }
     for (i = 0; i < p; ++i) {
-        int8 gi = kbytes[i];
+        int8 gi = (int8) kbytes[i];
         int8 gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (int16) (gi0 - (gi & (gi0 << 1)));
     }
 
     mult1024(fg, f, g);
@@ -289,7 +289,7 @@ int PQCLEAN_SNTRUP857_AVX2_crypto_core_mult3sntrup857(unsigned char *outbytes, c
     }
 
     for (i = 0; i < p; ++i) {
-        outbytes[i] = h[i];
+        outbytes[i] = (unsigned char) h[i];
     }
 
     return 0;
diff --git a/crypto_kem/sntrup857/avx2/crypto_core_multsntrup857.c b/crypto_kem/sntrup857/avx2/crypto_core_multsntrup857.c
index 3cd25ff6..898c7297 100644
--- a/crypto_kem/sntrup857/avx2/crypto_core_multsntrup857.c
+++ b/crypto_kem/sntrup857/avx2/crypto_core_multsntrup857.c
@@ -398,9 +398,9 @@ int PQCLEAN_SNTRUP857_AVX2_crypto_core_multsntrup857(unsigned char *outbytes, co
         store_x16(&f[i], x);
     }
     for (i = 0; i < p; ++i) {
-        int8 gi = kbytes[i];
+        int8 gi = (int8) kbytes[i];
         int8 gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (int8) (gi0 - (gi & (gi0 << 1)));
     }
 
     mult1024(fg, f, g);
diff --git a/crypto_kem/sntrup857/avx2/crypto_core_weightsntrup857.c b/crypto_kem/sntrup857/avx2/crypto_core_weightsntrup857.c
index 5df7914a..c8a37134 100644
--- a/crypto_kem/sntrup857/avx2/crypto_core_weightsntrup857.c
+++ b/crypto_kem/sntrup857/avx2/crypto_core_weightsntrup857.c
@@ -37,8 +37,8 @@ int PQCLEAN_SNTRUP857_AVX2_crypto_core_weightsntrup857(unsigned char *outbytes,
     sum = _mm256_hadd_epi16(sum, sum);
     /* want sum[0]+sum[8] */
 
-    weight = _mm256_extract_epi16(sum, 0);
-    weight += _mm256_extract_epi16(sum, 8);
+    weight = (int16) _mm256_extract_epi16(sum, 0);
+    weight += (int16) _mm256_extract_epi16(sum, 8);
 
     PQCLEAN_SNTRUP857_AVX2_crypto_encode_int16(outbytes, &weight);
     return 0;
diff --git a/crypto_kem/sntrup857/avx2/crypto_core_wforcesntrup857.c b/crypto_kem/sntrup857/avx2/crypto_core_wforcesntrup857.c
index 889de6f9..61264db3 100644
--- a/crypto_kem/sntrup857/avx2/crypto_core_wforcesntrup857.c
+++ b/crypto_kem/sntrup857/avx2/crypto_core_wforcesntrup857.c
@@ -17,7 +17,7 @@ int PQCLEAN_SNTRUP857_AVX2_crypto_core_wforcesntrup857(unsigned char *out, const
     crypto_core_weight((unsigned char *) &weight, in);
     PQCLEAN_SNTRUP857_AVX2_crypto_decode_int16(&weight, (unsigned char *) &weight);
 
-    mask = (weight - w) | (w - weight);
+    mask = (int16) ((weight - w) | (w - weight));
     mask >>= 15;
     maskvec = _mm256_set1_epi16((short) ~mask);
 
diff --git a/crypto_kem/sntrup857/avx2/crypto_decode_857x1723.c b/crypto_kem/sntrup857/avx2/crypto_decode_857x1723.c
index 336f1b6b..2691eb2b 100644
--- a/crypto_kem/sntrup857/avx2/crypto_decode_857x1723.c
+++ b/crypto_kem/sntrup857/avx2/crypto_decode_857x1723.c
@@ -10,7 +10,7 @@ static inline int16 mullo(int16 x, int16 y) {
 }
 
 static inline int16 mulhi(int16 x, int16 y) {
-    return (x * (int32)y) >> 16;
+    return (int16) ((x * (int32)y) >> 16);
 }
 
 static inline __m256i add(__m256i x, __m256i y) {
@@ -79,7 +79,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
     a0 = mulhi(a0, 276) - mulhi(mullo(a0, -22580), 743); /* -374...374 */
     a0 += s[2 * i + 0]; /* -374...629 */
     a0 += (a0 >> 15) & 743; /* 0...742 */
-    a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+    a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
     a1 = mullo(a1, -3881);
 
     /* invalid inputs might need reduction mod 14044 */
@@ -100,7 +100,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
     a0 -= 436; /* -670..>37 */
     a0 += (a0 >> 15) & 436; /* -234...435 */
     a0 += (a0 >> 15) & 436; /* 0...435 */
-    a1 = (a2 << 6) + ((s[i] - a0) >> 2);
+    a1 = (int16) ((a2 << 6) + ((s[i] - a0) >> 2));
     a1 = mullo(a1, 2405);
 
     /* invalid inputs might need reduction mod 8246 */
@@ -117,7 +117,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
         a0 -= 436; /* -670..>37 */
         a0 += (a0 >> 15) & 436; /* -234...435 */
         a0 += (a0 >> 15) & 436; /* 0...435 */
-        a1 = (a2 << 6) + ((s[i] - a0) >> 2);
+        a1 = (int16) ((a2 << 6) + ((s[i] - a0) >> 2));
         a1 = mullo(a1, 2405);
 
         /* invalid inputs might need reduction mod 436 */
@@ -139,7 +139,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
         a0 -= 334; /* -501..>103 */
         a0 += (a0 >> 15) & 334; /* -167...333 */
         a0 += (a0 >> 15) & 334; /* 0...333 */
-        a1 = (a2 << 7) + ((s[i] - a0) >> 1);
+        a1 = (int16) ((a2 << 7) + ((s[i] - a0) >> 1));
         a1 = mullo(a1, -22761);
 
         /* invalid inputs might need reduction mod 334 */
@@ -160,7 +160,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
     a0 -= 292; /* -438..>125 */
     a0 += (a0 >> 15) & 292; /* -146...291 */
     a0 += (a0 >> 15) & 292; /* 0...291 */
-    a1 = (a2 << 6) + ((s[i] - a0) >> 2);
+    a1 = (int16) ((a2 << 6) + ((s[i] - a0) >> 2));
     a1 = mullo(a1, -3591);
 
     /* invalid inputs might need reduction mod 7229 */
@@ -177,7 +177,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
         a0 -= 292; /* -438..>125 */
         a0 += (a0 >> 15) & 292; /* -146...291 */
         a0 += (a0 >> 15) & 292; /* 0...291 */
-        a1 = (a2 << 6) + ((s[i] - a0) >> 2);
+        a1 = (int16) ((a2 << 6) + ((s[i] - a0) >> 2));
         a1 = mullo(a1, -3591);
 
         /* invalid inputs might need reduction mod 292 */
@@ -199,7 +199,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
         a0 -= 273; /* -410..>118 */
         a0 += (a0 >> 15) & 273; /* -137...272 */
         a0 += (a0 >> 15) & 273; /* 0...272 */
-        a1 = (a2 << 8) + s[i] - a0;
+        a1 = (int16) ((a2 << 8) + s[i] - a0);
         a1 = mullo(a1, 4081);
 
         /* invalid inputs might need reduction mod 273 */
@@ -218,7 +218,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
     a0 = mulhi(a0, -259) - mulhi(mullo(a0, -3971), 4225); /* -2178...2112 */
     a0 += s[1 * i + 0]; /* -2178...2367 */
     a0 += (a0 >> 15) & 4225; /* 0...4224 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, 12161);
 
     /* invalid inputs might need reduction mod 438 */
@@ -272,7 +272,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
     a0 += s[1 * i + 0]; /* -33...287 */
     a0 = mulhi(a0, 16) - mulhi(mullo(a0, -1008), 65); /* -33...32 */
     a0 += (a0 >> 15) & 65; /* 0...64 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, 4033);
 
     /* invalid inputs might need reduction mod 1723 */
@@ -391,7 +391,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x1723(void *v, const unsigned char
 
     /* R1 ------> R0: reconstruct mod 857*[1723] */
 
-    R0[856] = 3 * R1[428] - 2583;
+    R0[856] = (int16) (3 * R1[428] - 2583);
     s -= 428;
     i = 412;
     for (;;) {
diff --git a/crypto_kem/sntrup857/avx2/crypto_decode_857x5167.c b/crypto_kem/sntrup857/avx2/crypto_decode_857x5167.c
index be710422..59b6969d 100644
--- a/crypto_kem/sntrup857/avx2/crypto_decode_857x5167.c
+++ b/crypto_kem/sntrup857/avx2/crypto_decode_857x5167.c
@@ -10,7 +10,7 @@ static inline int16 mullo(int16 x, int16 y) {
 }
 
 static inline int16 mulhi(int16 x, int16 y) {
-    return (x * (int32)y) >> 16;
+    return (int16) ((x * (int32)y) >> 16);
 }
 
 static inline __m256i add(__m256i x, __m256i y) {
@@ -78,7 +78,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x5167(void *v, const unsigned char
     a0 = mulhi(a0, -1248) - mulhi(mullo(a0, -3064), 5476); /* -3050...2738 */
     a0 += s[1 * i + 0]; /* -3050...2993 */
     a0 += (a0 >> 15) & 5476; /* 0...5475 */
-    a1 = (a2 << 6) + ((s[i] - a0) >> 2);
+    a1 = (int16) ((a2 << 6) + ((s[i] - a0) >> 2));
     a1 = mullo(a1, -3351);
 
     /* invalid inputs might need reduction mod 291 */
@@ -98,7 +98,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x5167(void *v, const unsigned char
     a0 += s[1 * i + 0]; /* -37...294 */
     a0 = mulhi(a0, -28) - mulhi(mullo(a0, -886), 74); /* -38...37 */
     a0 += (a0 >> 15) & 74; /* 0...73 */
-    a1 = (a2 << 7) + ((s[i] - a0) >> 1);
+    a1 = (int16) ((a2 << 7) + ((s[i] - a0) >> 1));
     a1 = mullo(a1, 7085);
 
     /* invalid inputs might need reduction mod 1004 */
@@ -112,7 +112,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x5167(void *v, const unsigned char
         a2 = a0 = R9[i];
         a0 = mulhi(a0, -28) - mulhi(mullo(a0, -886), 74); /* -44...37 */
         a0 += (a0 >> 15) & 74; /* 0...73 */
-        a1 = (a2 - a0) >> 1;
+        a1 = (int16) (a2 - a0) >> 1;
         a1 = mullo(a1, 7085);
 
         /* invalid inputs might need reduction mod 74 */
@@ -134,7 +134,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x5167(void *v, const unsigned char
         a0 = mulhi(a0, -302) - mulhi(mullo(a0, -7647), 2194); /* -1104...1102 */
         a0 += s[2 * i + 0]; /* -1104...1357 */
         a0 += (a0 >> 15) & 2194; /* 0...2193 */
-        a1 = (a2 << 15) + (s[2 * i + 1] << 7) + ((s[2 * i] - a0) >> 1);
+        a1 = (int16) ((a2 << 15) + (s[2 * i + 1] << 7) + ((s[2 * i] - a0) >> 1));
         a1 = mullo(a1, 11769);
 
         /* invalid inputs might need reduction mod 2194 */
@@ -155,7 +155,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x5167(void *v, const unsigned char
     a0 = mulhi(a0, 1807) - mulhi(mullo(a0, -1399), 11991); /* -6161...6180 */
     a0 += s[2 * i + 0]; /* -6161...6435 */
     a0 += (a0 >> 15) & 11991; /* 0...11990 */
-    a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+    a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
     a1 = mullo(a1, -23321);
 
     /* invalid inputs might need reduction mod 5483 */
@@ -172,7 +172,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x5167(void *v, const unsigned char
         a0 = mulhi(a0, 1807) - mulhi(mullo(a0, -1399), 11991); /* -6161...6180 */
         a0 += s[2 * i + 0]; /* -6161...6435 */
         a0 += (a0 >> 15) & 11991; /* 0...11990 */
-        a1 = (s[2 * i + 1] << 8) + s[2 * i] - a0;
+        a1 = (int16) ((s[2 * i + 1] << 8) + s[2 * i] - a0);
         a1 = mullo(a1, -23321);
 
         /* invalid inputs might need reduction mod 11991 */
@@ -192,7 +192,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x5167(void *v, const unsigned char
         a0 = mulhi(a0, 64) - mulhi(mullo(a0, -9576), 1752); /* -876...892 */
         a0 += s[1 * i + 0]; /* -876...1147 */
         a0 += (a0 >> 15) & 1752; /* 0...1751 */
-        a1 = (a2 << 5) + ((s[i] - a0) >> 3);
+        a1 = (int16) ((a2 << 5) + ((s[i] - a0) >> 3));
         a1 = mullo(a1, -1197);
 
         /* invalid inputs might need reduction mod 1752 */
@@ -211,7 +211,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x5167(void *v, const unsigned char
     a0 = mulhi(a0, 658) - mulhi(mullo(a0, -1566), 10713); /* -5357...5521 */
     a0 += s[1 * i + 0]; /* -5357...5776 */
     a0 += (a0 >> 15) & 10713; /* 0...10712 */
-    a1 = (a2 << 8) + s[i] - a0;
+    a1 = (int16) ((a2 << 8) + s[i] - a0);
     a1 = mullo(a1, -14743);
 
     /* invalid inputs might need reduction mod 131 */
@@ -266,7 +266,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857x5167(void *v, const unsigned char
     a0 = mulhi(a0, 280) - mulhi(mullo(a0, -10131), 1656); /* -832...832 */
     a0 += s[2 * i + 0]; /* -832...1087 */
     a0 += (a0 >> 15) & 1656; /* 0...1655 */
-    a1 = (a2 << 13) + (s[2 * i + 1] << 5) + ((s[2 * i] - a0) >> 3);
+    a1 = (int16) ((a2 << 13) + (s[2 * i + 1] << 5) + ((s[2 * i] - a0) >> 3));
     a1 = mullo(a1, 1583);
 
     /* invalid inputs might need reduction mod 5167 */
diff --git a/crypto_kem/sntrup857/avx2/crypto_decode_857xint16.c b/crypto_kem/sntrup857/avx2/crypto_decode_857xint16.c
index d52df0c3..8fc25e62 100644
--- a/crypto_kem/sntrup857/avx2/crypto_decode_857xint16.c
+++ b/crypto_kem/sntrup857/avx2/crypto_decode_857xint16.c
@@ -8,8 +8,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_decode_857xint16(void *v, const unsigned char
     for (i = 0; i < 857; ++i) {
         uint16_t u0 = s[0];
         uint16_t u1 = s[1];
-        u1 <<= 8;
-        *x = u0 | u1;
+        *x = (uint16_t) (u0 | (u1 << 8));
         x += 1;
         s += 2;
     }
diff --git a/crypto_kem/sntrup857/avx2/crypto_decode_int16.c b/crypto_kem/sntrup857/avx2/crypto_decode_int16.c
index a3a53a47..d92e2bf3 100644
--- a/crypto_kem/sntrup857/avx2/crypto_decode_int16.c
+++ b/crypto_kem/sntrup857/avx2/crypto_decode_int16.c
@@ -4,6 +4,6 @@
 void PQCLEAN_SNTRUP857_AVX2_crypto_decode_int16(void *x, const unsigned char *s) {
     uint16_t u0 = s[0];
     uint16_t u1 = s[1];
-    u1 <<= 8;
+    u1 = (uint16_t) (u1 << 8);
     *(uint16_t *) x = u0 | u1;
 }
diff --git a/crypto_kem/sntrup857/avx2/crypto_encode_857x1723.c b/crypto_kem/sntrup857/avx2/crypto_encode_857x1723.c
index 8ae91a55..605677b3 100644
--- a/crypto_kem/sntrup857/avx2/crypto_encode_857x1723.c
+++ b/crypto_kem/sntrup857/avx2/crypto_encode_857x1723.c
@@ -42,26 +42,26 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x1723(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
-    R[428] = (((R0[856] + 2583) & 16383) * 10923) >> 15;
+    R[428] = (uint16) ((((R0[856] + 2583) & 16383) * 10923) >> 15);
 
     reading = (uint16 *) R;
     writing = R;
@@ -145,14 +145,14 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x1723(unsigned char *out, const voi
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)65;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[106];
     r1 = R[107];
     r2 = r0 + r1 * (uint32)65;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[53] = r2;
+    R[53] = (uint16) r2;
 
     reading = (uint16 *) R;
     writing = R;
@@ -194,9 +194,9 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x1723(unsigned char *out, const voi
     r0 = R[52];
     r1 = R[53];
     r2 = r0 + r1 * (uint32)4225;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[26] = r2;
+    R[26] = (uint16) r2;
 
     reading = (uint16 *) R;
     writing = R;
@@ -220,22 +220,22 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x1723(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -245,18 +245,18 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x1723(unsigned char *out, const voi
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)292;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 3; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)334;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[3] = R[6];
 
@@ -264,20 +264,20 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x1723(unsigned char *out, const voi
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)436;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)743;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/sntrup857/avx2/crypto_encode_857x1723round.c b/crypto_kem/sntrup857/avx2/crypto_encode_857x1723round.c
index 7d9937a1..87439d76 100644
--- a/crypto_kem/sntrup857/avx2/crypto_encode_857x1723round.c
+++ b/crypto_kem/sntrup857/avx2/crypto_encode_857x1723round.c
@@ -44,26 +44,26 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x1723round(unsigned char *out, cons
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
-    R[428] = (((3 * ((10923 * R0[856] + 16384) >> 15) + 2583) & 16383) * 10923) >> 15;
+    R[428] = (uint16) ((((3 * ((10923 * R0[856] + 16384) >> 15) + 2583) & 16383) * 10923) >> 15);
 
     reading = (uint16 *) R;
     writing = R;
@@ -147,14 +147,14 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x1723round(unsigned char *out, cons
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)65;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[106];
     r1 = R[107];
     r2 = r0 + r1 * (uint32)65;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[53] = r2;
+    R[53] = (uint16) r2;
 
     reading = (uint16 *) R;
     writing = R;
@@ -196,9 +196,9 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x1723round(unsigned char *out, cons
     r0 = R[52];
     r1 = R[53];
     r2 = r0 + r1 * (uint32)4225;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[26] = r2;
+    R[26] = (uint16) r2;
 
     reading = (uint16 *) R;
     writing = R;
@@ -222,22 +222,22 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x1723round(unsigned char *out, cons
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -247,18 +247,18 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x1723round(unsigned char *out, cons
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)292;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 3; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)334;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[3] = R[6];
 
@@ -266,20 +266,20 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x1723round(unsigned char *out, cons
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)436;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)743;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/sntrup857/avx2/crypto_encode_857x5167.c b/crypto_kem/sntrup857/avx2/crypto_encode_857x5167.c
index 1dbc4f29..896f12cb 100644
--- a/crypto_kem/sntrup857/avx2/crypto_encode_857x5167.c
+++ b/crypto_kem/sntrup857/avx2/crypto_encode_857x5167.c
@@ -82,22 +82,22 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x5167(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -125,22 +125,22 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x5167(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -168,33 +168,33 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x5167(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
     r0 = R[106];
     r1 = R[107];
     r2 = r0 + r1 * (uint32)1656;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[53] = r2;
+    R[53] = (uint16) r2;
 
     reading = (uint16 *) R;
     writing = R;
@@ -236,9 +236,9 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x5167(unsigned char *out, const voi
     r0 = R[52];
     r1 = R[53];
     r2 = r0 + r1 * (uint32)10713;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[26] = r2;
+    R[26] = (uint16) r2;
 
     reading = (uint16 *) R;
     writing = R;
@@ -262,22 +262,22 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x5167(unsigned char *out, const voi
                                 ));
         x = _mm256_permute4x64_epi64(x, 0xd8);
         _mm_storeu_si128((__m128i *) writing, _mm256_extractf128_si256(x, 0));
-        s0 = _mm256_extract_epi32(x, 4);
-        *out++ = s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 4);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
-        s0 = _mm256_extract_epi32(x, 6);
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
+        s0 = (uint32) _mm256_extract_epi32(x, 6);
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         s0 >>= 8;
-        *out++ = s0;
+        *out++ = (unsigned char) s0;
         reading += 16;
         writing += 8;
     }
@@ -287,45 +287,45 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857x5167(unsigned char *out, const voi
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)11991;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 3; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)2194;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[3] = R[6];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)74;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     r0 = R[2];
     r1 = R[3];
     r2 = r0 + r1 * (uint32)74;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[1] = r2;
+    R[1] = (uint16) r2;
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)5476;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/sntrup857/avx2/crypto_encode_857xint16.c b/crypto_kem/sntrup857/avx2/crypto_encode_857xint16.c
index 7c889f7a..9ae26814 100644
--- a/crypto_kem/sntrup857/avx2/crypto_encode_857xint16.c
+++ b/crypto_kem/sntrup857/avx2/crypto_encode_857xint16.c
@@ -7,7 +7,7 @@ void PQCLEAN_SNTRUP857_AVX2_crypto_encode_857xint16(unsigned char *s, const void
 
     for (i = 0; i < 857; ++i) {
         uint16_t u = *x++;
-        *s++ = u;
-        *s++ = u >> 8;
+        *s++ = (unsigned char) u;
+        *s++ = (unsigned char) (u >> 8);
     }
 }
diff --git a/crypto_kem/sntrup857/avx2/crypto_encode_int16.c b/crypto_kem/sntrup857/avx2/crypto_encode_int16.c
index 33767274..5696d24c 100644
--- a/crypto_kem/sntrup857/avx2/crypto_encode_int16.c
+++ b/crypto_kem/sntrup857/avx2/crypto_encode_int16.c
@@ -4,6 +4,6 @@
 
 void PQCLEAN_SNTRUP857_AVX2_crypto_encode_int16(unsigned char *s, const void *x) {
     uint16 u = *(const uint16 *) x;
-    s[0] = u;
-    s[1] = u >> 8;
+    s[0] = (unsigned char) u;
+    s[1] = (unsigned char) (u >> 8);
 }
diff --git a/crypto_kem/sntrup857/avx2/crypto_sort_int32.c b/crypto_kem/sntrup857/avx2/crypto_sort_int32.c
index a438d7d3..ecd7b3b8 100644
--- a/crypto_kem/sntrup857/avx2/crypto_sort_int32.c
+++ b/crypto_kem/sntrup857/avx2/crypto_sort_int32.c
@@ -44,7 +44,7 @@ static void minmax_vector(int32 *x, int32 *y, size_t n) {
         int32x8_MINMAX(x0, y0);
         int32x8_store(x + n - 8, x0);
         int32x8_store(y + n - 8, y0);
-        n &= ~7;
+        n &= ~(size_t) 7;
     }
     do {
         int32x8 x0 = int32x8_load(x);
diff --git a/crypto_kem/sntrup857/avx2/crypto_verify_1184.c b/crypto_kem/sntrup857/avx2/crypto_verify_1184.c
index 20fb5f4c..d854ffb6 100644
--- a/crypto_kem/sntrup857/avx2/crypto_verify_1184.c
+++ b/crypto_kem/sntrup857/avx2/crypto_verify_1184.c
@@ -27,10 +27,10 @@ int PQCLEAN_SNTRUP857_AVX2_crypto_verify_1184(const unsigned char *x, const unsi
     diff |= _mm256_srli_epi32(diff, 16);
     diff |= _mm256_srli_epi64(diff, 32);
 
-    differentbits = _mm256_extract_epi8(diff, 0);
-    differentbits |= _mm256_extract_epi8(diff, 8);
-    differentbits |= _mm256_extract_epi8(diff, 16);
-    differentbits |= _mm256_extract_epi8(diff, 24);
+    differentbits = (unsigned int) _mm256_extract_epi8(diff, 0);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 8);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 16);
+    differentbits |= (unsigned int) _mm256_extract_epi8(diff, 24);
 
     return (int) (1 & ((differentbits - 1) >> 8)) - 1;
 }
diff --git a/crypto_kem/sntrup857/avx2/kem.c b/crypto_kem/sntrup857/avx2/kem.c
index 1cbfdf24..97772835 100644
--- a/crypto_kem/sntrup857/avx2/kem.c
+++ b/crypto_kem/sntrup857/avx2/kem.c
@@ -65,7 +65,7 @@ static void Rq_recip3(Fq *out, const small *in) {
 static void Hash(unsigned char *out, const unsigned char *in, int inlen) {
     unsigned char h[64];
     int i;
-    sha512(h, in, inlen);
+    sha512(h, in, (size_t) inlen);
     for (i = 0; i < 32; ++i) {
         out[i] = h[i];
     }
@@ -103,7 +103,7 @@ static void Short_random(small *out) {
     }
     PQCLEAN_SNTRUP857_AVX2_crypto_sort_uint32(L, ppadsort);
     for (i = 0; i < p; ++i) {
-        out[i] = (L[i] & 3) - 1;
+        out[i] = (small) ((L[i] & 3) - 1);
     }
 }
 
@@ -115,7 +115,7 @@ static void Small_random(small *out) {
         L[i] = urandom32();
     }
     for (i = 0; i < p; ++i) {
-        out[i] = (((L[i] & 0x3fffffff) * 3) >> 30) - 1;
+        out[i] = (small) ((((L[i] & 0x3fffffff) * 3) >> 30) - 1);
     }
 }
 
@@ -248,13 +248,13 @@ int PQCLEAN_SNTRUP857_AVX2_crypto_kem_dec(unsigned char *k, const unsigned char
         Hide(x, cnew, r_enc, r, pk, cache);
         mask = crypto_verify_clen(c, cnew);
         for (i = 0; i < Small_bytes; ++i) {
-            r_enc[i + 1] ^= mask & (r_enc[i + 1] ^ rho[i]);
+            r_enc[i + 1] ^= (unsigned char) (mask & (r_enc[i + 1] ^ rho[i]));
         }
         Hash(x + 1, r_enc, 1 + Small_bytes); /* XXX: can instead do cmov on cached hash of rho */
         for (i = 0; i < Ciphertexts_bytes + Confirm_bytes; ++i) {
             x[1 + Hash_bytes + i] = c[i];
         }
-        x[0] = 1 + mask;
+        x[0] = (unsigned char) (1 + mask);
         Hash(k, x, sizeof x);
     }
     return 0;
diff --git a/crypto_kem/sntrup857/clean/Makefile b/crypto_kem/sntrup857/clean/Makefile
index abe07fce..9c5e1649 100644
--- a/crypto_kem/sntrup857/clean/Makefile
+++ b/crypto_kem/sntrup857/clean/Makefile
@@ -4,7 +4,7 @@ LIB=libsntrup857_clean.a
 HEADERS=api.h crypto_core_inv3sntrup857.h crypto_core_invsntrup857.h crypto_core_mult3sntrup857.h crypto_core_multsntrup857.h crypto_core_scale3sntrup857.h crypto_core_weightsntrup857.h crypto_core_wforcesntrup857.h crypto_decode_857x1723.h crypto_decode_857x3.h crypto_decode_857x5167.h crypto_decode_857xint16.h crypto_decode_857xint32.h crypto_encode_857x1723.h crypto_encode_857x1723round.h crypto_encode_857x3.h crypto_encode_857x5167.h crypto_encode_857xfreeze3.h crypto_encode_857xint16.h crypto_encode_int16.h crypto_sort_int32.h crypto_sort_uint32.h crypto_stream_aes256ctr.h crypto_verify_1184.h params.h 
 OBJECTS=crypto_core_inv3sntrup857.o crypto_core_invsntrup857.o crypto_core_mult3sntrup857.o crypto_core_multsntrup857.o crypto_core_scale3sntrup857.o crypto_core_weightsntrup857.o crypto_core_wforcesntrup857.o crypto_decode_857x1723.o crypto_decode_857x3.o crypto_decode_857x5167.o crypto_decode_857xint16.o crypto_decode_857xint32.o crypto_encode_857x1723.o crypto_encode_857x1723round.o crypto_encode_857x3.o crypto_encode_857x5167.o crypto_encode_857xfreeze3.o crypto_encode_857xint16.o crypto_encode_int16.o crypto_sort_int32.o crypto_sort_uint32.o crypto_stream_aes256ctr.o crypto_verify_1184.o kem.o 
 
-CFLAGS=-O3 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -std=c99 -I../../../common $(EXTRAFLAGS)
+CFLAGS=-O3 -Wall -Wextra -Wpedantic -Wvla -Werror -Wredundant-decls -Wmissing-prototypes -Wconversion -std=c99 -I../../../common $(EXTRAFLAGS)
 
 all: $(LIB)
 
diff --git a/crypto_kem/sntrup857/clean/crypto_core_inv3sntrup857.c b/crypto_kem/sntrup857/clean/crypto_core_inv3sntrup857.c
index 234b2ad4..60f313ed 100644
--- a/crypto_kem/sntrup857/clean/crypto_core_inv3sntrup857.c
+++ b/crypto_kem/sntrup857/clean/crypto_core_inv3sntrup857.c
@@ -13,16 +13,16 @@
 
 /* return -1 if x!=0; else return 0 */
 static int int16_nonzero_mask(int16 x) {
-    uint16 u = x; /* 0, else 1...65535 */
+    uint16 u = (uint16) x; /* 0, else 1...65535 */
     uint32 v = u; /* 0, else 1...65535 */
     v = -v; /* 0, else 2^32-65535...2^32-1 */
     v >>= 31; /* 0, else 1 */
-    return -v; /* 0, else -1 */
+    return -(int) v; /* 0, else -1 */
 }
 
 /* return -1 if x<0; otherwise return 0 */
 static int int16_negative_mask(int16 x) {
-    uint16 u = x;
+    uint16 u = (uint16) x;
     u >>= 15;
     return -(int) u;
     /* alternative with gcc -fwrapv: */
@@ -36,7 +36,7 @@ typedef int8 small;
 
 /* works for -16384 <= x < 16384 */
 static small F3_freeze(int16 x) {
-    return x - 3 * ((10923 * x + 16384) >> 15);
+    return (small) (x - 3 * ((10923 * x + 16384) >> 15));
 }
 
 /* byte p of output is 0 if recip succeeded; else -1 */
@@ -61,7 +61,7 @@ int PQCLEAN_SNTRUP857_CLEAN_crypto_core_inv3sntrup857(unsigned char *outbytes, c
     f[p - 1] = f[p] = -1;
     for (i = 0; i < p; ++i) {
         small i1 = in[i] & 1;
-        g[p - 1 - i] = i1 - (in[i] & (i1 << 1));
+        g[p - 1 - i] = (small) (i1 - (in[i] & (i1 << 1)));
     }
     g[p] = 0;
 
@@ -74,24 +74,24 @@ int PQCLEAN_SNTRUP857_CLEAN_crypto_core_inv3sntrup857(unsigned char *outbytes, c
         v[0] = 0;
 
         sign = -g[0] * f[0];
-        swap = int16_negative_mask(-delta) & int16_nonzero_mask(g[0]);
+        swap = int16_negative_mask(-(int16) delta) & int16_nonzero_mask(g[0]);
         delta ^= swap & (delta ^ -delta);
         delta += 1;
 
         for (i = 0; i < p + 1; ++i) {
             t = swap & (f[i] ^ g[i]);
-            f[i] ^= t;
-            g[i] ^= t;
+            f[i] ^= (small) t;
+            g[i] ^= (small) t;
             t = swap & (v[i] ^ r[i]);
-            v[i] ^= t;
-            r[i] ^= t;
+            v[i] ^= (small) t;
+            r[i] ^= (small) t;
         }
 
         for (i = 0; i < p + 1; ++i) {
-            g[i] = F3_freeze(g[i] + sign * f[i]);
+            g[i] = F3_freeze((int16) (g[i] + sign * f[i]));
         }
         for (i = 0; i < p + 1; ++i) {
-            r[i] = F3_freeze(r[i] + sign * v[i]);
+            r[i] = F3_freeze((int16) (r[i] + sign * v[i]));
         }
 
         for (i = 0; i < p; ++i) {
@@ -102,9 +102,9 @@ int PQCLEAN_SNTRUP857_CLEAN_crypto_core_inv3sntrup857(unsigned char *outbytes, c
 
     sign = f[0];
     for (i = 0; i < p; ++i) {
-        out[i] = sign * v[p - 1 - i];
+        out[i] = (small) sign * v[p - 1 - i];
     }
 
-    out[p] = int16_nonzero_mask(delta);
+    out[p] = (small) int16_nonzero_mask((int16) delta);
     return 0;
 }
diff --git a/crypto_kem/sntrup857/clean/crypto_core_invsntrup857.c b/crypto_kem/sntrup857/clean/crypto_core_invsntrup857.c
index eb9823b8..383f2951 100644
--- a/crypto_kem/sntrup857/clean/crypto_core_invsntrup857.c
+++ b/crypto_kem/sntrup857/clean/crypto_core_invsntrup857.c
@@ -13,16 +13,16 @@
 
 /* return -1 if x!=0; else return 0 */
 static int int16_nonzero_mask(int16 x) {
-    uint16 u = x; /* 0, else 1...65535 */
+    uint16 u = (uint16) x; /* 0, else 1...65535 */
     uint32 v = u; /* 0, else 1...65535 */
     v = -v; /* 0, else 2^32-65535...2^32-1 */
     v >>= 31; /* 0, else 1 */
-    return -v; /* 0, else -1 */
+    return -(int) v; /* 0, else -1 */
 }
 
 /* return -1 if x<0; otherwise return 0 */
 static int int16_negative_mask(int16 x) {
-    uint16 u = x;
+    uint16 u = (uint16) x;
     u >>= 15;
     return -(int) u;
     /* alternative with gcc -fwrapv: */
@@ -40,7 +40,7 @@ typedef int16 Fq;
 static Fq Fq_freeze(int32 x) {
     x -= q * ((q18 * x) >> 18);
     x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    return (Fq) x;
 }
 
 static Fq Fq_recip(Fq a1) {
@@ -91,17 +91,17 @@ int PQCLEAN_SNTRUP857_CLEAN_crypto_core_invsntrup857(unsigned char *outbytes, co
         }
         v[0] = 0;
 
-        swap = int16_negative_mask(-delta) & int16_nonzero_mask(g[0]);
+        swap = int16_negative_mask((int16) - delta) & int16_nonzero_mask(g[0]);
         delta ^= swap & (delta ^ -delta);
         delta += 1;
 
         for (i = 0; i < p + 1; ++i) {
             t = swap & (f[i] ^ g[i]);
-            f[i] ^= t;
-            g[i] ^= t;
+            f[i] ^= (Fq) t;
+            g[i] ^= (Fq) t;
             t = swap & (v[i] ^ r[i]);
-            v[i] ^= t;
-            r[i] ^= t;
+            v[i] ^= (Fq) t;
+            r[i] ^= (Fq) t;
         }
 
         f0 = f[0];
@@ -126,6 +126,6 @@ int PQCLEAN_SNTRUP857_CLEAN_crypto_core_invsntrup857(unsigned char *outbytes, co
 
     crypto_encode_pxint16(outbytes, out);
 
-    outbytes[2 * p] = int16_nonzero_mask(delta);
+    outbytes[2 * p] = (unsigned char) int16_nonzero_mask((int16) delta);
     return 0;
 }
diff --git a/crypto_kem/sntrup857/clean/crypto_core_mult3sntrup857.c b/crypto_kem/sntrup857/clean/crypto_core_mult3sntrup857.c
index 02d8697b..d5391808 100644
--- a/crypto_kem/sntrup857/clean/crypto_core_mult3sntrup857.c
+++ b/crypto_kem/sntrup857/clean/crypto_core_mult3sntrup857.c
@@ -8,7 +8,7 @@ typedef int8 small;
 
 /* works for -16384 <= x < 16384 */
 static small F3_freeze(int16 x) {
-    return x - 3 * ((10923 * x + 16384) >> 15);
+    return (small) (x - 3 * ((10923 * x + 16384) >> 15));
 }
 
 int PQCLEAN_SNTRUP857_CLEAN_crypto_core_mult3sntrup857(unsigned char *outbytes, const unsigned char *inbytes, const unsigned char *kbytes) {
@@ -20,27 +20,27 @@ int PQCLEAN_SNTRUP857_CLEAN_crypto_core_mult3sntrup857(unsigned char *outbytes,
     int i, j;
 
     for (i = 0; i < p; ++i) {
-        small fi = inbytes[i];
+        small fi = (small) inbytes[i];
         small fi0 = fi & 1;
-        f[i] = fi0 - (fi & (fi0 << 1));
+        f[i] = (small) (fi0 - (fi & (fi0 << 1)));
     }
     for (i = 0; i < p; ++i) {
-        small gi = kbytes[i];
+        small gi = (small) kbytes[i];
         small gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (small) (gi0 - (gi & (gi0 << 1)));
     }
 
     for (i = 0; i < p; ++i) {
         result = 0;
         for (j = 0; j <= i; ++j) {
-            result += f[j] * g[i - j];
+            result += (int16) (f[j] * g[i - j]);
         }
         fg[i] = F3_freeze(result);
     }
     for (i = p; i < p + p - 1; ++i) {
         result = 0;
         for (j = i - p + 1; j < p; ++j) {
-            result += f[j] * g[i - j];
+            result += (int16) (f[j] * g[i - j]);
         }
         fg[i] = F3_freeze(result);
     }
diff --git a/crypto_kem/sntrup857/clean/crypto_core_multsntrup857.c b/crypto_kem/sntrup857/clean/crypto_core_multsntrup857.c
index 80474ff8..2066e528 100644
--- a/crypto_kem/sntrup857/clean/crypto_core_multsntrup857.c
+++ b/crypto_kem/sntrup857/clean/crypto_core_multsntrup857.c
@@ -14,7 +14,7 @@ typedef int16 Fq;
 static Fq Fq_freeze(int32 x) {
     x -= q * ((q18 * x) >> 18);
     x -= q * ((q27 * x + 67108864) >> 27);
-    return x;
+    return (Fq) x;
 }
 
 int PQCLEAN_SNTRUP857_CLEAN_crypto_core_multsntrup857(unsigned char *outbytes, const unsigned char *inbytes, const unsigned char *kbytes) {
@@ -30,9 +30,9 @@ int PQCLEAN_SNTRUP857_CLEAN_crypto_core_multsntrup857(unsigned char *outbytes, c
     }
 
     for (i = 0; i < p; ++i) {
-        small gi = kbytes[i];
+        small gi = (small) kbytes[i];
         small gi0 = gi & 1;
-        g[i] = gi0 - (gi & (gi0 << 1));
+        g[i] = (small) (gi0 - (gi & (gi0 << 1)));
     }
 
     for (i = 0; i < p; ++i) {
diff --git a/crypto_kem/sntrup857/clean/crypto_core_wforcesntrup857.c b/crypto_kem/sntrup857/clean/crypto_core_wforcesntrup857.c
index 6a8dc8fd..b7d5b1d8 100644
--- a/crypto_kem/sntrup857/clean/crypto_core_wforcesntrup857.c
+++ b/crypto_kem/sntrup857/clean/crypto_core_wforcesntrup857.c
@@ -12,11 +12,11 @@ typedef int8 small;
 
 /* return -1 if x!=0; else return 0 */
 static int int16_nonzero_mask(int16 x) {
-    uint16 u = x; /* 0, else 1...65535 */
+    uint16 u = (uint16) x; /* 0, else 1...65535 */
     uint32 v = u; /* 0, else 1...65535 */
     v = -v; /* 0, else 2^32-65535...2^32-1 */
     v >>= 31; /* 0, else 1 */
-    return -v; /* 0, else -1 */
+    return -(int) v; /* 0, else -1 */
 }
 
 /* 0 if Weightw_is(r), else -1 */
@@ -27,7 +27,7 @@ static int Weightw_mask(const small *r) {
     for (i = 0; i < p; ++i) {
         weight += r[i] & 1;
     }
-    return int16_nonzero_mask(weight - w);
+    return int16_nonzero_mask((int16) (weight - w));
 }
 
 /* out = in if bottom bits of in have weight w */
@@ -39,10 +39,10 @@ int PQCLEAN_SNTRUP857_CLEAN_crypto_core_wforcesntrup857(unsigned char *outbytes,
 
     mask = Weightw_mask(in); /* 0 if weight w, else -1 */
     for (i = 0; i < w; ++i) {
-        out[i] = ((in[i] ^ 1) & ~mask) ^ 1;
+        out[i] = (small) (((in[i] ^ 1) & ~mask) ^ 1);
     }
     for (i = w; i < p; ++i) {
-        out[i] = in[i] & ~mask;
+        out[i] = (small) (in[i] & ~mask);
     }
     return 0;
 }
diff --git a/crypto_kem/sntrup857/clean/crypto_decode_857x1723.c b/crypto_kem/sntrup857/clean/crypto_decode_857x1723.c
index ab803b68..3664a899 100644
--- a/crypto_kem/sntrup857/clean/crypto_decode_857x1723.c
+++ b/crypto_kem/sntrup857/clean/crypto_decode_857x1723.c
@@ -30,7 +30,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
 
     *q = 0;
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 2^31 qpart <= xv <= 2^31 qpart + 2^31-1 */
     /* 2^31 qpart m <= xvm <= 2^31 qpart m + (2^31-1)m */
     /* 2^31 qpart m <= 2^31 x <= 2^31 qpart m + (2^31-1)m + x(m-1) */
@@ -42,7 +42,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += qpart;
     /* x <= 49146 */
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 0 <= newx <= (1-1/2^31)m + x(m-1)/2^31 */
     /* 0 <= newx <= m + 49146(2^14-1)/2^31 */
     /* 0 <= newx <= m + 0.4 */
@@ -59,7 +59,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += mask;
     /* x < m */
 
-    *r = x;
+    *r = (uint16) x;
 }
 
 static uint16 uint32_mod_uint14(uint32 x, uint16 m) {
@@ -80,7 +80,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x1723(void *v, const unsigned char
     r1 = 0;
     r1 = (r1 << 8) | *--s;
     r1 = uint32_mod_uint14(r1, 160); /* needed only for invalid inputs */
-    R10[0] = r1;
+    R10[0] = (uint16) r1;
 
     r2 = R10[0];
     r2 = (r2 << 8) | *--s;
@@ -88,20 +88,20 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x1723(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 743);
     R9[0] = r0;
     r1 = uint32_mod_uint14(r1, 14044); /* needed only for invalid inputs */
-    R9[1] = r1;
+    R9[1] = (uint16) r1;
 
     r2 = R9[1];
     r2 = (r2 << 8) | *--s;
     uint32_divmod_uint14(&r1, &r0, r2, 436);
     R8[2] = r0;
     r1 = uint32_mod_uint14(r1, 8246); /* needed only for invalid inputs */
-    R8[3] = r1;
+    R8[3] = (uint16) r1;
     r2 = R9[0];
     r2 = (r2 << 8) | *--s;
     uint32_divmod_uint14(&r1, &r0, r2, 436);
     R8[0] = r0;
     r1 = uint32_mod_uint14(r1, 436); /* needed only for invalid inputs */
-    R8[1] = r1;
+    R8[1] = (uint16) r1;
 
     R7[6] = R8[3];
     for (i = 2; i >= 0; --i) {
@@ -110,7 +110,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x1723(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 334);
         R7[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 334); /* needed only for invalid inputs */
-        R7[2 * i + 1] = r1;
+        R7[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R7[6];
@@ -118,14 +118,14 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x1723(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 292);
     R6[12] = r0;
     r1 = uint32_mod_uint14(r1, 7229); /* needed only for invalid inputs */
-    R6[13] = r1;
+    R6[13] = (uint16) r1;
     for (i = 5; i >= 0; --i) {
         r2 = R7[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 292);
         R6[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 292); /* needed only for invalid inputs */
-        R6[2 * i + 1] = r1;
+        R6[2 * i + 1] = (uint16) r1;
     }
 
     R5[26] = R6[13];
@@ -135,7 +135,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x1723(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 273);
         R5[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 273); /* needed only for invalid inputs */
-        R5[2 * i + 1] = r1;
+        R5[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R5[26];
@@ -143,7 +143,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x1723(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 4225);
     R4[52] = r0;
     r1 = uint32_mod_uint14(r1, 438); /* needed only for invalid inputs */
-    R4[53] = r1;
+    R4[53] = (uint16) r1;
     for (i = 25; i >= 0; --i) {
         r2 = R5[i];
         r2 = (r2 << 8) | *--s;
@@ -151,7 +151,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x1723(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 4225);
         R4[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 4225); /* needed only for invalid inputs */
-        R4[2 * i + 1] = r1;
+        R4[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R4[53];
@@ -159,13 +159,13 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x1723(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 65);
     R3[106] = r0;
     r1 = uint32_mod_uint14(r1, 1723); /* needed only for invalid inputs */
-    R3[107] = r1;
+    R3[107] = (uint16) r1;
     for (i = 52; i >= 0; --i) {
         r2 = R4[i];
         uint32_divmod_uint14(&r1, &r0, r2, 65);
         R3[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 65); /* needed only for invalid inputs */
-        R3[2 * i + 1] = r1;
+        R3[2 * i + 1] = (uint16) r1;
     }
 
     R2[214] = R3[107];
@@ -176,7 +176,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x1723(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 2053);
         R2[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 2053); /* needed only for invalid inputs */
-        R2[2 * i + 1] = r1;
+        R2[2 * i + 1] = (uint16) r1;
     }
 
     R1[428] = R2[214];
@@ -187,16 +187,16 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x1723(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 11597);
         R1[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 11597); /* needed only for invalid inputs */
-        R1[2 * i + 1] = r1;
+        R1[2 * i + 1] = (uint16) r1;
     }
 
-    R0[856] = 3 * R1[428] - 2583;
+    R0[856] = (int16) (3 * R1[428] - 2583);
     for (i = 427; i >= 0; --i) {
         r2 = R1[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 1723);
-        R0[2 * i] = 3 * r0 - 2583;
+        R0[2 * i] = (int16) (3 * r0 - 2583);
         r1 = uint32_mod_uint14(r1, 1723); /* needed only for invalid inputs */
-        R0[2 * i + 1] = 3 * r1 - 2583;
+        R0[2 * i + 1] = (int16) (3 * r1 - 2583);
     }
 }
diff --git a/crypto_kem/sntrup857/clean/crypto_decode_857x5167.c b/crypto_kem/sntrup857/clean/crypto_decode_857x5167.c
index 1068effe..67a01738 100644
--- a/crypto_kem/sntrup857/clean/crypto_decode_857x5167.c
+++ b/crypto_kem/sntrup857/clean/crypto_decode_857x5167.c
@@ -30,7 +30,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
 
     *q = 0;
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 2^31 qpart <= xv <= 2^31 qpart + 2^31-1 */
     /* 2^31 qpart m <= xvm <= 2^31 qpart m + (2^31-1)m */
     /* 2^31 qpart m <= 2^31 x <= 2^31 qpart m + (2^31-1)m + x(m-1) */
@@ -42,7 +42,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += qpart;
     /* x <= 49146 */
 
-    qpart = (x * (uint64)v) >> 31;
+    qpart = (uint32) ((x * (uint64)v) >> 31);
     /* 0 <= newx <= (1-1/2^31)m + x(m-1)/2^31 */
     /* 0 <= newx <= m + 49146(2^14-1)/2^31 */
     /* 0 <= newx <= m + 0.4 */
@@ -59,7 +59,7 @@ static void uint32_divmod_uint14(uint32 *q, uint16 *r, uint32 x, uint16 m) {
     *q += mask;
     /* x < m */
 
-    *r = x;
+    *r = (uint16) x;
 }
 
 static uint16 uint32_mod_uint14(uint32 x, uint16 m) {
@@ -81,26 +81,26 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x5167(void *v, const unsigned char
     r1 = (r1 << 8) | *--s;
     r1 = (r1 << 8) | *--s;
     r1 = uint32_mod_uint14(r1, 6225); /* needed only for invalid inputs */
-    R10[0] = r1;
+    R10[0] = (uint16) r1;
 
     r2 = R10[0];
     r2 = (r2 << 8) | *--s;
     uint32_divmod_uint14(&r1, &r0, r2, 5476);
     R9[0] = r0;
     r1 = uint32_mod_uint14(r1, 291); /* needed only for invalid inputs */
-    R9[1] = r1;
+    R9[1] = (uint16) r1;
 
     r2 = R9[1];
     r2 = (r2 << 8) | *--s;
     uint32_divmod_uint14(&r1, &r0, r2, 74);
     R8[2] = r0;
     r1 = uint32_mod_uint14(r1, 1004); /* needed only for invalid inputs */
-    R8[3] = r1;
+    R8[3] = (uint16) r1;
     r2 = R9[0];
     uint32_divmod_uint14(&r1, &r0, r2, 74);
     R8[0] = r0;
     r1 = uint32_mod_uint14(r1, 74); /* needed only for invalid inputs */
-    R8[1] = r1;
+    R8[1] = (uint16) r1;
 
     R7[6] = R8[3];
     for (i = 2; i >= 0; --i) {
@@ -110,7 +110,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x5167(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 2194);
         R7[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 2194); /* needed only for invalid inputs */
-        R7[2 * i + 1] = r1;
+        R7[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R7[6];
@@ -119,7 +119,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x5167(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 11991);
     R6[12] = r0;
     r1 = uint32_mod_uint14(r1, 5483); /* needed only for invalid inputs */
-    R6[13] = r1;
+    R6[13] = (uint16) r1;
     for (i = 5; i >= 0; --i) {
         r2 = R7[i];
         r2 = (r2 << 8) | *--s;
@@ -127,7 +127,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x5167(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 11991);
         R6[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 11991); /* needed only for invalid inputs */
-        R6[2 * i + 1] = r1;
+        R6[2 * i + 1] = (uint16) r1;
     }
 
     R5[26] = R6[13];
@@ -137,7 +137,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x5167(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 1752);
         R5[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 1752); /* needed only for invalid inputs */
-        R5[2 * i + 1] = r1;
+        R5[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R5[26];
@@ -145,7 +145,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x5167(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 10713);
     R4[52] = r0;
     r1 = uint32_mod_uint14(r1, 131); /* needed only for invalid inputs */
-    R4[53] = r1;
+    R4[53] = (uint16) r1;
     for (i = 25; i >= 0; --i) {
         r2 = R5[i];
         r2 = (r2 << 8) | *--s;
@@ -153,7 +153,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x5167(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 10713);
         R4[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 10713); /* needed only for invalid inputs */
-        R4[2 * i + 1] = r1;
+        R4[2 * i + 1] = (uint16) r1;
     }
 
     r2 = R4[53];
@@ -162,14 +162,14 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x5167(void *v, const unsigned char
     uint32_divmod_uint14(&r1, &r0, r2, 1656);
     R3[106] = r0;
     r1 = uint32_mod_uint14(r1, 5167); /* needed only for invalid inputs */
-    R3[107] = r1;
+    R3[107] = (uint16) r1;
     for (i = 52; i >= 0; --i) {
         r2 = R4[i];
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 1656);
         R3[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 1656); /* needed only for invalid inputs */
-        R3[2 * i + 1] = r1;
+        R3[2 * i + 1] = (uint16) r1;
     }
 
     R2[214] = R3[107];
@@ -179,7 +179,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x5167(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 651);
         R2[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 651); /* needed only for invalid inputs */
-        R2[2 * i + 1] = r1;
+        R2[2 * i + 1] = (uint16) r1;
     }
 
     R1[428] = R2[214];
@@ -189,17 +189,17 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857x5167(void *v, const unsigned char
         uint32_divmod_uint14(&r1, &r0, r2, 408);
         R1[2 * i] = r0;
         r1 = uint32_mod_uint14(r1, 408); /* needed only for invalid inputs */
-        R1[2 * i + 1] = r1;
+        R1[2 * i + 1] = (uint16) r1;
     }
 
-    R0[856] = R1[428] - 2583;
+    R0[856] = (int16) (R1[428] - 2583);
     for (i = 427; i >= 0; --i) {
         r2 = R1[i];
         r2 = (r2 << 8) | *--s;
         r2 = (r2 << 8) | *--s;
         uint32_divmod_uint14(&r1, &r0, r2, 5167);
-        R0[2 * i] = r0 - 2583;
+        R0[2 * i] = (int16) (r0 - 2583);
         r1 = uint32_mod_uint14(r1, 5167); /* needed only for invalid inputs */
-        R0[2 * i + 1] = r1 - 2583;
+        R0[2 * i + 1] = (int16) (r1 - 2583);
     }
 }
diff --git a/crypto_kem/sntrup857/clean/crypto_decode_857xint16.c b/crypto_kem/sntrup857/clean/crypto_decode_857xint16.c
index 7841b093..ceb224bc 100644
--- a/crypto_kem/sntrup857/clean/crypto_decode_857xint16.c
+++ b/crypto_kem/sntrup857/clean/crypto_decode_857xint16.c
@@ -8,8 +8,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_decode_857xint16(void *v, const unsigned cha
     for (i = 0; i < 857; ++i) {
         uint16_t u0 = s[0];
         uint16_t u1 = s[1];
-        u1 <<= 8;
-        *x = u0 | u1;
+        *x = (uint16_t) (u0 | (u1 << 8));
         x += 1;
         s += 2;
     }
diff --git a/crypto_kem/sntrup857/clean/crypto_encode_857x1723.c b/crypto_kem/sntrup857/clean/crypto_encode_857x1723.c
index 7a33a9a6..9fc987d2 100644
--- a/crypto_kem/sntrup857/clean/crypto_encode_857x1723.c
+++ b/crypto_kem/sntrup857/clean/crypto_encode_857x1723.c
@@ -15,24 +15,24 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857x1723(unsigned char *out, const vo
     uint32 r2;
 
     for (i = 0; i < 428; ++i) {
-        r0 = (((R0[2 * i] + 2583) & 16383) * 10923) >> 15;
-        r1 = (((R0[2 * i + 1] + 2583) & 16383) * 10923) >> 15;
+        r0 = (uint16) ((((R0[2 * i] + 2583) & 16383) * 10923) >> 15);
+        r1 = (uint16) ((((R0[2 * i + 1] + 2583) & 16383) * 10923) >> 15);
         r2 = r0 + r1 * (uint32)1723;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
-    R[428] = (((R0[856] + 2583) & 16383) * 10923) >> 15;
+    R[428] = (uint16) ((((R0[856] + 2583) & 16383) * 10923) >> 15);
 
     for (i = 0; i < 214; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)11597;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[214] = R[428];
 
@@ -40,11 +40,11 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857x1723(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)2053;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[107] = R[214];
 
@@ -52,39 +52,39 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857x1723(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)65;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[106];
     r1 = R[107];
     r2 = r0 + r1 * (uint32)65;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[53] = r2;
+    R[53] = (uint16) r2;
 
     for (i = 0; i < 26; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)4225;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[52];
     r1 = R[53];
     r2 = r0 + r1 * (uint32)4225;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[26] = r2;
+    R[26] = (uint16) r2;
 
     for (i = 0; i < 13; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)273;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[13] = R[26];
 
@@ -92,18 +92,18 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857x1723(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)292;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 3; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)334;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[3] = R[6];
 
@@ -111,20 +111,20 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857x1723(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)436;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)743;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/sntrup857/clean/crypto_encode_857x1723round.c b/crypto_kem/sntrup857/clean/crypto_encode_857x1723round.c
index fd73c0f5..2b73e9c8 100644
--- a/crypto_kem/sntrup857/clean/crypto_encode_857x1723round.c
+++ b/crypto_kem/sntrup857/clean/crypto_encode_857x1723round.c
@@ -11,7 +11,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857x1723round(unsigned char *out, con
     int i;
 
     for (i = 0; i < p; ++i) {
-        x[i] = 3 * ((10923 * a[i] + 16384) >> 15);
+        x[i] = (int16) (3 * ((10923 * a[i] + 16384) >> 15));
     }
     PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857x1723(out, x);
 }
diff --git a/crypto_kem/sntrup857/clean/crypto_encode_857x3.c b/crypto_kem/sntrup857/clean/crypto_encode_857x3.c
index de61c551..2db8d7ea 100644
--- a/crypto_kem/sntrup857/clean/crypto_encode_857x3.c
+++ b/crypto_kem/sntrup857/clean/crypto_encode_857x3.c
@@ -11,9 +11,9 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857x3(unsigned char *s, const void *v
 
     for (i = 0; i < p / 4; ++i) {
         x = *f++ + 1;
-        x += (*f++ + 1) << 2;
-        x += (*f++ + 1) << 4;
-        x += (*f++ + 1) << 6;
+        x += (uint8) ((*f++ + 1) << 2);
+        x += (uint8) ((*f++ + 1) << 4);
+        x += (uint8) ((*f++ + 1) << 6);
         *s++ = x;
     }
     x = *f++ + 1;
diff --git a/crypto_kem/sntrup857/clean/crypto_encode_857x5167.c b/crypto_kem/sntrup857/clean/crypto_encode_857x5167.c
index 064d5249..43318fb3 100644
--- a/crypto_kem/sntrup857/clean/crypto_encode_857x5167.c
+++ b/crypto_kem/sntrup857/clean/crypto_encode_857x5167.c
@@ -18,11 +18,11 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857x5167(unsigned char *out, const vo
         r0 = (R0[2 * i] + 2583) & 16383;
         r1 = (R0[2 * i + 1] + 2583) & 16383;
         r2 = r0 + r1 * (uint32)5167;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[428] = (R0[856] + 2583) & 16383;
 
@@ -30,9 +30,9 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857x5167(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)408;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[214] = R[428];
 
@@ -40,9 +40,9 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857x5167(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)651;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[107] = R[214];
 
@@ -50,43 +50,43 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857x5167(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1656;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[106];
     r1 = R[107];
     r2 = r0 + r1 * (uint32)1656;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[53] = r2;
+    R[53] = (uint16) r2;
 
     for (i = 0; i < 26; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)10713;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     r0 = R[52];
     r1 = R[53];
     r2 = r0 + r1 * (uint32)10713;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[26] = r2;
+    R[26] = (uint16) r2;
 
     for (i = 0; i < 13; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)1752;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[13] = R[26];
 
@@ -94,45 +94,45 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857x5167(unsigned char *out, const vo
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)11991;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
 
     for (i = 0; i < 3; ++i) {
         r0 = R[2 * i];
         r1 = R[2 * i + 1];
         r2 = r0 + r1 * (uint32)2194;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        *out++ = r2;
+        *out++ = (unsigned char) r2;
         r2 >>= 8;
-        R[i] = r2;
+        R[i] = (uint16) r2;
     }
     R[3] = R[6];
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)74;
-    R[0] = r2;
+    R[0] = (uint16) r2;
     r0 = R[2];
     r1 = R[3];
     r2 = r0 + r1 * (uint32)74;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[1] = r2;
+    R[1] = (uint16) r2;
 
     r0 = R[0];
     r1 = R[1];
     r2 = r0 + r1 * (uint32)5476;
-    *out++ = r2;
+    *out++ = (unsigned char) r2;
     r2 >>= 8;
-    R[0] = r2;
+    R[0] = (uint16) r2;
 
     r0 = R[0];
-    *out++ = r0;
+    *out++ = (unsigned char) r0;
     r0 >>= 8;
-    *out++ = r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
+    *out++ = (unsigned char) r0; /*clang-analyzer-deadcode.DeadStores*/ /*r0 >>= 8;*/
 }
diff --git a/crypto_kem/sntrup857/clean/crypto_encode_857xfreeze3.c b/crypto_kem/sntrup857/clean/crypto_encode_857xfreeze3.c
index 99fc3bc5..901b9c94 100644
--- a/crypto_kem/sntrup857/clean/crypto_encode_857xfreeze3.c
+++ b/crypto_kem/sntrup857/clean/crypto_encode_857xfreeze3.c
@@ -12,7 +12,7 @@
 /* and F3_freeze(x) is in {-2,-1,0,1,2} */
 
 static inline unsigned char F3_freeze(int16 x) {
-    return x - 3 * ((10923 * x + 16384) >> 15);
+    return (unsigned char) (x - 3 * ((10923 * x + 16384) >> 15));
 }
 
 void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857xfreeze3(unsigned char *s, const void *v) {
diff --git a/crypto_kem/sntrup857/clean/crypto_encode_857xint16.c b/crypto_kem/sntrup857/clean/crypto_encode_857xint16.c
index d496ac17..a89e9f16 100644
--- a/crypto_kem/sntrup857/clean/crypto_encode_857xint16.c
+++ b/crypto_kem/sntrup857/clean/crypto_encode_857xint16.c
@@ -7,7 +7,7 @@ void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_857xint16(unsigned char *s, const voi
 
     for (i = 0; i < 857; ++i) {
         uint16_t u = *x++;
-        *s++ = u;
-        *s++ = u >> 8;
+        *s++ = (unsigned char) u;
+        *s++ = (unsigned char) (u >> 8);
     }
 }
diff --git a/crypto_kem/sntrup857/clean/crypto_encode_int16.c b/crypto_kem/sntrup857/clean/crypto_encode_int16.c
index 30756273..7746afc5 100644
--- a/crypto_kem/sntrup857/clean/crypto_encode_int16.c
+++ b/crypto_kem/sntrup857/clean/crypto_encode_int16.c
@@ -4,6 +4,6 @@
 
 void PQCLEAN_SNTRUP857_CLEAN_crypto_encode_int16(unsigned char *s, const void *x) {
     uint16 u = *(const uint16 *) x;
-    s[0] = u;
-    s[1] = u >> 8;
+    s[0] = (unsigned char) u;
+    s[1] = (unsigned char) (u >> 8);
 }
diff --git a/crypto_kem/sntrup857/clean/kem.c b/crypto_kem/sntrup857/clean/kem.c
index a555e254..057a17c6 100644
--- a/crypto_kem/sntrup857/clean/kem.c
+++ b/crypto_kem/sntrup857/clean/kem.c
@@ -65,7 +65,7 @@ static void Rq_recip3(Fq *out, const small *in) {
 static void Hash(unsigned char *out, const unsigned char *in, int inlen) {
     unsigned char h[64];
     int i;
-    sha512(h, in, inlen);
+    sha512(h, in, (size_t) inlen);
     for (i = 0; i < 32; ++i) {
         out[i] = h[i];
     }
@@ -103,7 +103,7 @@ static void Short_random(small *out) {
     }
     PQCLEAN_SNTRUP857_CLEAN_crypto_sort_uint32(L, ppadsort);
     for (i = 0; i < p; ++i) {
-        out[i] = (L[i] & 3) - 1;
+        out[i] = (small) ((L[i] & 3) - 1);
     }
 }
 
@@ -115,7 +115,7 @@ static void Small_random(small *out) {
         L[i] = urandom32();
     }
     for (i = 0; i < p; ++i) {
-        out[i] = (((L[i] & 0x3fffffff) * 3) >> 30) - 1;
+        out[i] = (small) ((((L[i] & 0x3fffffff) * 3) >> 30) - 1);
     }
 }
 
@@ -248,13 +248,13 @@ int PQCLEAN_SNTRUP857_CLEAN_crypto_kem_dec(unsigned char *k, const unsigned char
         Hide(x, cnew, r_enc, r, pk, cache);
         mask = crypto_verify_clen(c, cnew);
         for (i = 0; i < Small_bytes; ++i) {
-            r_enc[i + 1] ^= mask & (r_enc[i + 1] ^ rho[i]);
+            r_enc[i + 1] ^= (unsigned char) (mask & (r_enc[i + 1] ^ rho[i]));
         }
         Hash(x + 1, r_enc, 1 + Small_bytes); /* XXX: can instead do cmov on cached hash of rho */
         for (i = 0; i < Ciphertexts_bytes + Confirm_bytes; ++i) {
             x[1 + Hash_bytes + i] = c[i];
         }
-        x[0] = 1 + mask;
+        x[0] = (unsigned char) (1 + mask);
         Hash(k, x, sizeof x);
     }
     return 0;