diff --git a/ghost/admin/ember-cli-build.js b/ghost/admin/ember-cli-build.js
index b0a841e41d..e541a2b3dd 100644
--- a/ghost/admin/ember-cli-build.js
+++ b/ghost/admin/ember-cli-build.js
@@ -17,6 +17,10 @@ assetLocation = function (fileName) {
 
 module.exports = function (defaults) {
     var app = new EmberApp(defaults, {
+        babel: {
+            optional: ['es6.spec.symbols'],
+            includePolyfill: true
+        },
         outputPaths: {
             app: {
                 js: assetLocation('ghost.js')