diff --git a/feature-detects/es6/symbol.js b/feature-detects/es6/symbol.js
index 29aef4a8..30275473 100644
--- a/feature-detects/es6/symbol.js
+++ b/feature-detects/es6/symbol.js
@@ -20,7 +20,7 @@ Check if browser implements ECMAScript 6 Symbol per specification.
 */
 define(['Modernizr'], function(Modernizr) {
   Modernizr.addTest('es6symbol', !!(typeof(Symbol)==="function" &&
-    Symbol.for &&
+    Symbol['for'] &&
     Symbol.hasInstance &&
     Symbol.isConcatSpreadable &&
     Symbol.iterator &&