diff --git a/client/main.js b/client/main.js
index c6e2b3620..379f1d90b 100644
--- a/client/main.js
+++ b/client/main.js
@@ -1,6 +1,7 @@
 /* global io */
 /* eslint-disable no-new */
 
+require('core-js/modules/es5')
 var Karma = require('./karma')
 var StatusUpdater = require('./updater')
 var util = require('./util')