diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index b61453f..9afcc96 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -10216,6 +10216,10 @@
 void mbedtls_ssl_config_init( mbedtls_ssl_config *conf )
 {
     memset( conf, 0, sizeof( mbedtls_ssl_config ) );
+
+#if !defined(MBEDTLS_SSL_PROTO_TLS)
+    conf->transport = MBEDTLS_SSL_TRANSPORT_DATAGRAM;
+#endif
 }
 
 #if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)