diff --git a/src/crypto/hrss/hrss.cc b/src/crypto/hrss/hrss.cc
index 217c3fb10..5e5b207b9 100644
--- a/src/crypto/hrss/hrss.cc
+++ b/src/crypto/hrss/hrss.cc
@@ -1835,6 +1835,8 @@ static void poly_lift(struct poly *out, const struct poly *a) {
   poly_normalize(out);
 }
 
+namespace {
+
 struct public_key {
   struct poly ph;
 };
@@ -1845,6 +1847,8 @@ struct private_key {
   uint8_t hmac_key[32];
 };
 
+}  // namespace
+
 // public_key_from_external converts an external public key pointer into an
 // internal one. Externally the alignment is only specified to be eight bytes
 // but we need 16-byte alignment. We could annotate the external struct with
diff --git a/src/crypto/kyber/kyber.cc b/src/crypto/kyber/kyber.cc
index 77531040a..f21dc2f73 100644
--- a/src/crypto/kyber/kyber.cc
+++ b/src/crypto/kyber/kyber.cc
@@ -575,6 +575,8 @@ static void vector_decompress(vector *a, int bits) {
   }
 }
 
+namespace {
+
 struct public_key {
   vector t;
   uint8_t rho[32];
@@ -607,6 +609,8 @@ static struct private_key *private_key_from_external(
   return (struct private_key *)external;
 }
 
+}  // namespace
+
 // Calls |KYBER_generate_key_external_entropy| with random bytes from
 // |RAND_bytes|.
 void KYBER_generate_key(uint8_t out_encoded_public_key[KYBER_PUBLIC_KEY_BYTES],