diff --git a/api/js/login.js b/api/js/login.js
index 82bc5d7f18..b613fd5354 100644
--- a/api/js/login.js
+++ b/api/js/login.js
@@ -15,6 +15,14 @@ egw_LAB.wait(function()
 {
 	jQuery(document).ready(function()
 	{
+		// check if the browser supports ES6 and try to warn user
+		try {
+			Symbol();
+		}
+		catch (exception){
+			alert(egw.lang('Your browser is not new enough (JS ES6 compatible), you may experience some of the feautres not working.'));
+		}
+
 		// lock the device orientation in portrait view
 		if (screen.orientation && typeof screen.orientation.lock == 'function') screen.orientation.lock('portrait');
 		jQuery('.closeBtn').click(function (){