diff --git a/include/openssl/ssl.h b/include/openssl/ssl.h
index 36f61a6..e9eb236 100644
--- a/include/openssl/ssl.h
+++ b/include/openssl/ssl.h
@@ -3981,22 +3981,6 @@
 
 DECLARE_STACK_OF(SSL_CUSTOM_EXTENSION)
 
-struct ssl_cipher_st {
-  // name is the OpenSSL name for the cipher.
-  const char *name;
-  // standard_name is the IETF name for the cipher.
-  const char *standard_name;
-  // id is the cipher suite value bitwise OR-d with 0x03000000.
-  uint32_t id;
-
-  // algorithm_* are internal fields. See ssl/internal.h for their values.
-  uint32_t algorithm_mkey;
-  uint32_t algorithm_auth;
-  uint32_t algorithm_enc;
-  uint32_t algorithm_mac;
-  uint32_t algorithm_prf;
-};
-
 #define SSL_MAX_SSL_SESSION_ID_LENGTH 32
 #define SSL_MAX_SID_CTX_LENGTH 32
 #define SSL_MAX_MASTER_KEY_LENGTH 48
diff --git a/ssl/internal.h b/ssl/internal.h
index 2fb3614..9e67457 100644
--- a/ssl/internal.h
+++ b/ssl/internal.h
@@ -302,6 +302,26 @@
 
 // Cipher suites.
 
+}  // namespace bssl
+
+struct ssl_cipher_st {
+  // name is the OpenSSL name for the cipher.
+  const char *name;
+  // standard_name is the IETF name for the cipher.
+  const char *standard_name;
+  // id is the cipher suite value bitwise OR-d with 0x03000000.
+  uint32_t id;
+
+  // algorithm_* determine the cipher suite. See constants below for the values.
+  uint32_t algorithm_mkey;
+  uint32_t algorithm_auth;
+  uint32_t algorithm_enc;
+  uint32_t algorithm_mac;
+  uint32_t algorithm_prf;
+};
+
+namespace bssl {
+
 // Bits for |algorithm_mkey| (key exchange algorithm).
 #define SSL_kRSA 0x00000001u
 #define SSL_kECDHE 0x00000002u