diff --git a/app/assets/javascripts/discourse/initializers/message-bus.js.es6 b/app/assets/javascripts/discourse/initializers/message-bus.js.es6
index 650a9544a8a..3ce1a033c38 100644
--- a/app/assets/javascripts/discourse/initializers/message-bus.js.es6
+++ b/app/assets/javascripts/discourse/initializers/message-bus.js.es6
@@ -29,7 +29,7 @@ export default {
 
     messageBus.callbackInterval = siteSettings.anon_polling_interval;
     messageBus.backgroundCallbackInterval = siteSettings.background_polling_interval;
-    messageBus.baseUrl = siteSettings.long_polling_base_url;
+    messageBus.baseUrl = siteSettings.long_polling_base_url.replace(/\/$/, '') + '/';
 
     if (messageBus.baseUrl !== '/') {
       // zepto compatible, 1 param only