diff --git a/quic/core/crypto/tls_connection.h b/quic/core/crypto/tls_connection.h
index c15d920..4774ba6 100644
--- a/quic/core/crypto/tls_connection.h
+++ b/quic/core/crypto/tls_connection.h
@@ -69,7 +69,7 @@
   static enum ssl_encryption_level_t BoringEncryptionLevel(
       EncryptionLevel level);
 
-  SSL* ssl() { return ssl_.get(); }
+  SSL* ssl() const { return ssl_.get(); }
 
  protected:
   // TlsConnection does not take ownership of any of its arguments; they must