diff --git a/www/common/cryptpad-common.js b/www/common/cryptpad-common.js
index c5e4c02e6..520dff69b 100644
--- a/www/common/cryptpad-common.js
+++ b/www/common/cryptpad-common.js
@@ -1966,6 +1966,9 @@ define([
                 feedback("NO_ARRAYFILL");
             }
 
+            if (typeof(Symbol) === 'undefined') {
+                feedback('NO_SYMBOL');
+            }
             common.reportScreenDimensions();
             common.reportLanguage();