diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 950319a10..9f8192fd6 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -697,7 +697,7 @@
  *
  * \note  This option only works with the default software implementation of
  *        elliptic curve functionality. It is incompatible with
- *        MBEDTLS_ECP_ALT, MBEDTLS_ECDH_xxx_ALT and MBEDTLS_ECDSA_xxx_ALT.
+ *        MBEDTLS_ECP_ALT, MBEDTLS_ECDH_XXX_ALT and MBEDTLS_ECDSA_XXX_ALT.
  */
 //#define MBEDTLS_ECP_RESTARTABLE