diff --git a/app/assets/javascripts/discourse/lib/load-script.js.es6 b/app/assets/javascripts/discourse/lib/load-script.js.es6
index 700cd16776e..8baf4b905d8 100644
--- a/app/assets/javascripts/discourse/lib/load-script.js.es6
+++ b/app/assets/javascripts/discourse/lib/load-script.js.es6
@@ -77,7 +77,7 @@ export default function loadScript(url, opts) {
     // to dynamically load more JS. In that case, add the `scriptTag: true`
     // option.
     if (opts.scriptTag) {
-      if (Ember.Testing) {
+      if (Ember.testing) {
         throw `In test mode scripts cannot be loaded async ${cdnUrl}`;
       }
       loadWithTag(cdnUrl, cb);