--- a/common/corpus-common-addon/tests/helpers/start-app.js	Wed Feb 15 10:51:26 2017 +0100
+++ b/common/corpus-common-addon/tests/helpers/start-app.js	Wed Feb 15 22:53:45 2017 +0100
@@ -5,8 +5,8 @@
 export default function startApp(attrs) {
   let application;
 
-  // use defaults, but you can override
-  let attributes = Ember.assign({}, config.APP, attrs);
+  let attributes = Ember.merge({}, config.APP);
+  attributes = Ember.merge(attributes, attrs); // use defaults, but you can override;
 
   Ember.run(() => {
     application = Application.create(attributes);