fix: stricter check for browser environment

fczbkk · May 20, 2016 · 7725a1f · 7725a1f
1 parent b364aeb
commit 7725a1f
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/src/index.js b/src/index.js
@@ -9,7 +9,9 @@ import polyfill from './array-reduce-polyfill';
  */
 function isOldPrototype () {
   // do not even try outside browser
-  if (!window) {return false;}
+  if (typeof window === 'undefined') {
+    return false;
+  }
 
   const prototype_version = getNestedProperty(window, 'Prototype.Version');