diff --git a/src/querySelector.js b/src/querySelector.js
index 96bf2ec..a3fa818 100644
--- a/src/querySelector.js
+++ b/src/querySelector.js
@@ -23,7 +23,7 @@
   var originalElementGetElementsByTagNameNS = document.documentElement.getElementsByTagNameNS;
 
   var OriginalElement = window.Element;
-  var OriginalDocument = window.HTMLDocument;
+  var OriginalDocument = window.HTMLDocument || window.Document;
 
   function filterNodeList(list, index, result) {
     var wrappedItem = null;