Fix typo in comment
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 206c436..43fa449 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -6171,7 +6171,7 @@
             ssl_handshake_wrapup_free_hs_transform( ssl );
         }
     }
-#endif /* MBEDTLS_SSL_DTLS */
+#endif /* MBEDTLS_SSL_PROTO_DTLS */
 
     return( 0 );
 }