diff --git a/ssl/ssl_buffer.cc b/ssl/ssl_buffer.cc
index 579899b..c5b5608 100644
--- a/ssl/ssl_buffer.cc
+++ b/ssl/ssl_buffer.cc
@@ -12,6 +12,8 @@
  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
 
+#define BORINGSSL_INTERNAL_CXX_TYPES
+
 #include <openssl/ssl.h>
 
 #include <assert.h>
@@ -27,6 +29,8 @@
 #include "internal.h"
 
 
+namespace bssl {
+
 /* BIO uses int instead of size_t. No lengths will exceed uint16_t, so this will
  * not overflow. */
 static_assert(0xffff <= INT_MAX, "uint16_t does not fit in int");
@@ -289,3 +293,5 @@
 void ssl_write_buffer_clear(SSL *ssl) {
   clear_buffer(&ssl->s3->write_buffer);
 }
+
+}  // namespace bssl