diff --git a/src/vendor/core/dom/isNode.js b/src/vendor/core/dom/isNode.js
index 2b10439936..d47727701e 100644
--- a/src/vendor/core/dom/isNode.js
+++ b/src/vendor/core/dom/isNode.js
@@ -23,7 +23,7 @@
  */
 function isNode(object) {
   return !!(object && (
-    typeof Node !== 'undefined' ? object instanceof Node :
+    typeof Node === 'function' ? object instanceof Node :
       typeof object === 'object' &&
       typeof object.nodeType === 'number' &&
       typeof object.nodeName === 'string'