diff --git a/crypto_kem/newhope1024cca/clean/verify.c b/crypto_kem/newhope1024cca/clean/verify.c
index f2930ec0..f68c9328 100644
--- a/crypto_kem/newhope1024cca/clean/verify.c
+++ b/crypto_kem/newhope1024cca/clean/verify.c
@@ -22,7 +22,7 @@ int PQCLEAN_NEWHOPE1024CCA_CLEAN_verify(const unsigned char *a, const unsigned c
         r |= a[i] ^ b[i];
     }
 
-    r = (-r) >> 63;
+    r = (uint64_t)(-(int64_t)r) >> 63;
     return (int)r;
 }
 
diff --git a/crypto_kem/newhope1024cpa/clean/verify.c b/crypto_kem/newhope1024cpa/clean/verify.c
index 3cf20833..677e3ae9 100644
--- a/crypto_kem/newhope1024cpa/clean/verify.c
+++ b/crypto_kem/newhope1024cpa/clean/verify.c
@@ -22,7 +22,7 @@ int PQCLEAN_NEWHOPE1024CPA_CLEAN_verify(const unsigned char *a, const unsigned c
         r |= a[i] ^ b[i];
     }
 
-    r = (-r) >> 63;
+    r = (uint64_t)(-(int64_t)r) >> 63;
     return (int)r;
 }
 
diff --git a/crypto_kem/newhope512cca/clean/verify.c b/crypto_kem/newhope512cca/clean/verify.c
index 96694524..37e65f94 100644
--- a/crypto_kem/newhope512cca/clean/verify.c
+++ b/crypto_kem/newhope512cca/clean/verify.c
@@ -22,7 +22,7 @@ int PQCLEAN_NEWHOPE512CCA_CLEAN_verify(const unsigned char *a, const unsigned ch
         r |= a[i] ^ b[i];
     }
 
-    r = (-r) >> 63;
+    r = (uint64_t)(-(int64_t)r) >> 63;
     return (int)r;
 }
 
diff --git a/crypto_kem/newhope512cpa/clean/verify.c b/crypto_kem/newhope512cpa/clean/verify.c
index 471f052b..a03cf862 100644
--- a/crypto_kem/newhope512cpa/clean/verify.c
+++ b/crypto_kem/newhope512cpa/clean/verify.c
@@ -22,7 +22,7 @@ int PQCLEAN_NEWHOPE512CPA_CLEAN_verify(const unsigned char *a, const unsigned ch
         r |= a[i] ^ b[i];
     }
 
-    r = (-r) >> 63;
+    r = (uint64_t)(-(int64_t)r) >> 63;
     return (int)r;
 }