diff --git a/index.js b/index.js
index e1e7c32..1420f4c 100644
--- a/index.js
+++ b/index.js
@@ -267,6 +267,9 @@ function createClient(options) {
       if (haveCredentials) {
         joinServerRequest(onJoinServerResponse);
       } else {
+        if (packet.serverId != '-') {
+          debug('This server appears to be an online server and you are providing no password, the authentication will probably fail');
+        }
         sendEncryptionKeyResponse();
       }