diff --git a/webadmin.js b/webadmin.js
index cb7bbf6..fc4d72a 100644
--- a/webadmin.js
+++ b/webadmin.js
@@ -35,6 +35,10 @@ function init(options) {
     app.get('/', pageHome);
     app.post('/', doRestart);
 
+    if (!config.webadmin.listen_port) {
+        logger.warn('Not starting webadmin because missing config.webadmin.listen_port');
+    }
+
     app.listen(config.webadmin.listen_port, function () {
         logger.info('Webadmin listening on port ' + config.webadmin.listen_port);
     });