diff --git a/app/assets/javascripts/discourse/helpers/register-unbound.js.es6 b/app/assets/javascripts/discourse/helpers/register-unbound.js.es6
index 5296f4d5a8f..cb5f751bf05 100644
--- a/app/assets/javascripts/discourse/helpers/register-unbound.js.es6
+++ b/app/assets/javascripts/discourse/helpers/register-unbound.js.es6
@@ -26,6 +26,6 @@ export default function registerUnbound(name, fn) {
       }
     }
 
-    return fn(property, params);
+    return fn.apply(this,[property, params]);
   });
 }