diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index d9ab832..fb68a1c 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -4057,6 +4057,7 @@
     !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) && \
     !defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED)    && \
     !defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
+/* No certificate support -> dummy functions */
 int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl )
 {
     const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
@@ -4096,7 +4097,10 @@
     MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
     return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
 }
+
 #else
+/* Some certificate support -> implement write and parse */
+
 int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;