diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index c63b445..5177ce9 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -450,6 +450,7 @@
 
 int query_config( const char *config );
 
+#if defined(MBEDTLS_DEBUG_C)
 static void my_debug( void *ctx, int level,
                       const char *file, int line,
                       const char *str )
@@ -465,6 +466,7 @@
                      basename, line, level, str );
     fflush(  (FILE *) ctx  );
 }
+#endif /* MBEDTLS_DEBUG_C */
 
 
 #if !defined(MBEDTLS_SSL_CONF_RECV) && \
@@ -1777,7 +1779,9 @@
     mbedtls_ssl_conf_rng_ctx( &conf, &ctr_drbg );
 #endif
 
+#if defined(MBEDTLS_DEBUG_C)
     mbedtls_ssl_conf_dbg( &conf, my_debug, stdout );
+#endif
 
 #if !defined(MBEDTLS_SSL_CONF_READ_TIMEOUT)
     mbedtls_ssl_conf_read_timeout( &conf, opt.read_timeout );