diff --git a/include/mbedtls/mbedtls_config.h b/include/mbedtls/mbedtls_config.h
index c31a2cee52..f7d06d03a0 100644
--- a/include/mbedtls/mbedtls_config.h
+++ b/include/mbedtls/mbedtls_config.h
@@ -3103,7 +3103,7 @@
  * If the implementation here is empty, this will effectively disable the
  * checking of functions' return values.
  */
-//#define MBEDTLS_CHECK_RETURN __attribute__(__warn_unused_result__)
+//#define MBEDTLS_CHECK_RETURN __attribute__((__warn_unused_result__))
 
 /* PSA options */
 /**