diff --git a/crypto/asn1/asn1_test.cc b/crypto/asn1/asn1_test.cc
index d2adbba1..8b024427 100644
--- a/crypto/asn1/asn1_test.cc
+++ b/crypto/asn1/asn1_test.cc
@@ -40,7 +40,7 @@ static const uint8_t kTagOverflow[] = {
     0x1f, 0xff, 0xff, 0xff, 0xff, 0x7f, 0x01, 0x00,
 };
 
-bool TestLargeTags() {
+static bool TestLargeTags() {
   const uint8_t *p = kTag258;
   ScopedASN1_TYPE obj(d2i_ASN1_TYPE(NULL, &p, sizeof(kTag258)));
   if (obj) {
diff --git a/crypto/bio/pair.c b/crypto/bio/pair.c
index fba4be2c..2da2d203 100644
--- a/crypto/bio/pair.c
+++ b/crypto/bio/pair.c
@@ -742,7 +742,7 @@ static const BIO_METHOD methods_biop = {
     bio_free,     NULL /* no bio_callback_ctrl */
 };
 
-const BIO_METHOD *bio_s_bio(void) { return &methods_biop; }
+static const BIO_METHOD *bio_s_bio(void) { return &methods_biop; }
 
 int BIO_new_bio_pair(BIO** bio1_p, size_t writebuf1,
                      BIO** bio2_p, size_t writebuf2) {
diff --git a/crypto/bn/mul.c b/crypto/bn/mul.c
index d2d8fd8c..06e53ee0 100644
--- a/crypto/bn/mul.c
+++ b/crypto/bn/mul.c
@@ -66,7 +66,8 @@
 #define BN_SQR_RECURSIVE_SIZE_NORMAL BN_MUL_RECURSIVE_SIZE_NORMAL
 
 
-void bn_mul_normal(BN_ULONG *r, BN_ULONG *a, int na, BN_ULONG *b, int nb) {
+static void bn_mul_normal(BN_ULONG *r, BN_ULONG *a, int na, BN_ULONG *b,
+                          int nb) {
   BN_ULONG *rr;
 
   if (na < nb) {
diff --git a/crypto/conf/conf.c b/crypto/conf/conf.c
index 6bdcc4dc..eed07e6d 100644
--- a/crypto/conf/conf.c
+++ b/crypto/conf/conf.c
@@ -152,7 +152,7 @@ void NCONF_free(CONF *conf) {
   OPENSSL_free(conf);
 }
 
-CONF_VALUE *NCONF_new_section(const CONF *conf, const char *section) {
+static CONF_VALUE *NCONF_new_section(const CONF *conf, const char *section) {
   STACK_OF(CONF_VALUE) *sk = NULL;
   int ok = 0;
   CONF_VALUE *v = NULL, *old_value;
diff --git a/crypto/ec/ec_test.cc b/crypto/ec/ec_test.cc
index 3d80d5f4..ce9d99f3 100644
--- a/crypto/ec/ec_test.cc
+++ b/crypto/ec/ec_test.cc
@@ -122,7 +122,7 @@ static bool EncodeECPrivateKey(std::vector<uint8_t> *out, const EC_KEY *key) {
   return true;
 }
 
-bool Testd2i_ECPrivateKey() {
+static bool Testd2i_ECPrivateKey() {
   ScopedEC_KEY key = DecodeECPrivateKey(kECKeyWithoutPublic,
                                         sizeof(kECKeyWithoutPublic));
   if (!key) {
@@ -438,7 +438,7 @@ static bool TestArbitraryCurve() {
   return true;
 }
 
-bool TestAddingEqualPoints(int nid) {
+static bool TestAddingEqualPoints(int nid) {
   ScopedEC_KEY key(EC_KEY_new_by_curve_name(nid));
   if (!key) {
     return false;
diff --git a/crypto/ec/example_mul.c b/crypto/ec/example_mul.c
index ebb724fa..9db97d68 100644
--- a/crypto/ec/example_mul.c
+++ b/crypto/ec/example_mul.c
@@ -73,7 +73,7 @@
 #include <openssl/obj.h>
 
 
-int example_EC_POINT_mul(void) {
+static int example_EC_POINT_mul(void) {
   /* This example ensures that 10×∞ + G = G, in P-256. */
   EC_GROUP *group = NULL;
   EC_POINT *p = NULL, *result = NULL;
diff --git a/crypto/ec/p224-64.c b/crypto/ec/p224-64.c
index b433a75b..40f1c157 100644
--- a/crypto/ec/p224-64.c
+++ b/crypto/ec/p224-64.c
@@ -982,10 +982,10 @@ static void batch_mul(felem x_out, felem y_out, felem z_out,
 
 /* Takes the Jacobian coordinates (X, Y, Z) of a point and returns
  * (X', Y') = (X/Z^2, Y/Z^3) */
-int ec_GFp_nistp224_point_get_affine_coordinates(const EC_GROUP *group,
-                                                 const EC_POINT *point,
-                                                 BIGNUM *x, BIGNUM *y,
-                                                 BN_CTX *ctx) {
+static int ec_GFp_nistp224_point_get_affine_coordinates(const EC_GROUP *group,
+                                                        const EC_POINT *point,
+                                                        BIGNUM *x, BIGNUM *y,
+                                                        BN_CTX *ctx) {
   felem z1, z2, x_in, y_in, x_out, y_out;
   widefelem tmp;
 
@@ -1024,9 +1024,12 @@ int ec_GFp_nistp224_point_get_affine_coordinates(const EC_GROUP *group,
   return 1;
 }
 
-int ec_GFp_nistp224_points_mul(const EC_GROUP *group, EC_POINT *r,
-                               const BIGNUM *g_scalar, const EC_POINT *p_,
-                               const BIGNUM *p_scalar_, BN_CTX *ctx) {
+static int ec_GFp_nistp224_points_mul(const EC_GROUP *group,
+                                      EC_POINT *r,
+                                      const BIGNUM *g_scalar,
+                                      const EC_POINT *p_,
+                                      const BIGNUM *p_scalar_,
+                                      BN_CTX *ctx) {
   /* TODO: This function used to take |points| and |scalars| as arrays of
    * |num| elements. The code below should be simplified to work in terms of
    * |p_| and |p_scalar_|. */
diff --git a/crypto/ec/p256-64.c b/crypto/ec/p256-64.c
index 5be9a060..24778c46 100644
--- a/crypto/ec/p256-64.c
+++ b/crypto/ec/p256-64.c
@@ -1536,10 +1536,10 @@ static void batch_mul(felem x_out, felem y_out, felem z_out,
 
 /* Takes the Jacobian coordinates (X, Y, Z) of a point and returns (X', Y') =
  * (X/Z^2, Y/Z^3). */
-int ec_GFp_nistp256_point_get_affine_coordinates(const EC_GROUP *group,
-                                                 const EC_POINT *point,
-                                                 BIGNUM *x, BIGNUM *y,
-                                                 BN_CTX *ctx) {
+static int ec_GFp_nistp256_point_get_affine_coordinates(const EC_GROUP *group,
+                                                        const EC_POINT *point,
+                                                        BIGNUM *x, BIGNUM *y,
+                                                        BN_CTX *ctx) {
   felem z1, z2, x_in, y_in;
   smallfelem x_out, y_out;
   longfelem tmp;
@@ -1575,9 +1575,12 @@ int ec_GFp_nistp256_point_get_affine_coordinates(const EC_GROUP *group,
   return 1;
 }
 
-int ec_GFp_nistp256_points_mul(const EC_GROUP *group, EC_POINT *r,
-                               const BIGNUM *g_scalar, const EC_POINT *p_,
-                               const BIGNUM *p_scalar_, BN_CTX *ctx) {
+static int ec_GFp_nistp256_points_mul(const EC_GROUP *group,
+                                      EC_POINT *r,
+                                      const BIGNUM *g_scalar,
+                                      const EC_POINT *p_,
+                                      const BIGNUM *p_scalar_,
+                                      BN_CTX *ctx) {
   /* TODO: This function used to take |points| and |scalars| as arrays of
    * |num| elements. The code below should be simplified to work in terms of |p|
    * and |p_scalar|. */
diff --git a/crypto/rsa/padding.c b/crypto/rsa/padding.c
index 4d668706..12147ea4 100644
--- a/crypto/rsa/padding.c
+++ b/crypto/rsa/padding.c
@@ -274,8 +274,8 @@ int RSA_padding_add_none(uint8_t *to, unsigned to_len, const uint8_t *from,
   return 1;
 }
 
-int PKCS1_MGF1(uint8_t *mask, unsigned len, const uint8_t *seed,
-               unsigned seedlen, const EVP_MD *dgst) {
+static int PKCS1_MGF1(uint8_t *mask, unsigned len, const uint8_t *seed,
+                      unsigned seedlen, const EVP_MD *dgst) {
   unsigned outlen = 0;
   uint32_t i;
   uint8_t cnt[4];
diff --git a/ssl/ssl_ecdh.c b/ssl/ssl_ecdh.c
index 0ed9705d..6abd0ba2 100644
--- a/ssl/ssl_ecdh.c
+++ b/ssl/ssl_ecdh.c
@@ -84,9 +84,12 @@ err:
   return ret;
 }
 
-int ssl_ec_point_compute_secret(SSL_ECDH_CTX *ctx, uint8_t **out_secret,
-                                size_t *out_secret_len, uint8_t *out_alert,
-                                const uint8_t *peer_key, size_t peer_key_len) {
+static int ssl_ec_point_compute_secret(SSL_ECDH_CTX *ctx,
+                                       uint8_t **out_secret,
+                                       size_t *out_secret_len,
+                                       uint8_t *out_alert,
+                                       const uint8_t *peer_key,
+                                       size_t peer_key_len) {
   BIGNUM *private_key = (BIGNUM *)ctx->data;
   assert(private_key != NULL);
   *out_alert = SSL_AD_INTERNAL_ERROR;
diff --git a/tool/tool.cc b/tool/tool.cc
index b8250089..84f5598b 100644
--- a/tool/tool.cc
+++ b/tool/tool.cc
@@ -83,7 +83,7 @@ static void usage(const char *name) {
   }
 }
 
-tool_func_t FindTool(const std::string &name) {
+static tool_func_t FindTool(const std::string &name) {
   for (size_t i = 0;; i++) {
     const Tool &tool = kTools[i];
     if (tool.func == nullptr || name == tool.name) {