diff --git a/es6-shim.js b/es6-shim.js
index d7403d7f..b4739e65 100644
--- a/es6-shim.js
+++ b/es6-shim.js
@@ -1387,7 +1387,8 @@
     var isBadHex = isBadHexRegex.test.bind(isBadHexRegex);
     var NumberShim = (function () {
       // this is wrapped in an IIFE because of IE 6-8's wacky scoping issues with named function expressions.
-      var NumberShim = function Number(value) {
+      var NumberShim = function Number() {
+        var value = arguments[0];
         var primValue;
         if (arguments.length > 0) {
           primValue = Type.primitive(value) ? value : toPrimitive(value, 'number');