diff --git a/src/ShadowRenderer.js b/src/ShadowRenderer.js
index 736d9e0..36a9b8c 100644
--- a/src/ShadowRenderer.js
+++ b/src/ShadowRenderer.js
@@ -658,4 +658,4 @@
     remove: remove,
   };
 
-})(this.ShadowDOMPolyfill);
\ No newline at end of file
+})(window.ShadowDOMPolyfill);
diff --git a/src/querySelector.js b/src/querySelector.js
index d8ae54a..f1da41e 100644
--- a/src/querySelector.js
+++ b/src/querySelector.js
@@ -70,4 +70,4 @@
   scope.GetElementsByInterface = GetElementsByInterface;
   scope.SelectorsInterface = SelectorsInterface;
 
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers.js b/src/wrappers.js
index 9a4db8a..7e89655 100644
--- a/src/wrappers.js
+++ b/src/wrappers.js
@@ -2,7 +2,7 @@
 // Use of this source code is goverened by a BSD-style
 // license that can be found in the LICENSE file.
 
-var ShadowDOMPolyfill = {};
+window.ShadowDOMPolyfill = {};
 
 (function(scope) {
   'use strict';
@@ -371,4 +371,4 @@ var ShadowDOMPolyfill = {};
   scope.wrapIfNeeded = wrapIfNeeded;
   scope.wrappers = wrappers;
 
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/CanvasRenderingContext2D.js b/src/wrappers/CanvasRenderingContext2D.js
index 0b5c31d..2391a15 100644
--- a/src/wrappers/CanvasRenderingContext2D.js
+++ b/src/wrappers/CanvasRenderingContext2D.js
@@ -36,4 +36,4 @@
   registerWrapper(OriginalCanvasRenderingContext2D, CanvasRenderingContext2D);
 
   scope.wrappers.CanvasRenderingContext2D = CanvasRenderingContext2D;
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/CharacterData.js b/src/wrappers/CharacterData.js
index 0f94e77..146b9bd 100644
--- a/src/wrappers/CharacterData.js
+++ b/src/wrappers/CharacterData.js
@@ -31,4 +31,4 @@
                   document.createTextNode(''));
 
   scope.wrappers.CharacterData = CharacterData;
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/Document.js b/src/wrappers/Document.js
index c12830a..6f54f88 100644
--- a/src/wrappers/Document.js
+++ b/src/wrappers/Document.js
@@ -288,4 +288,4 @@
   scope.wrappers.DOMImplementation = DOMImplementation;
   scope.wrappers.Document = Document;
 
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/Element.js b/src/wrappers/Element.js
index 00efc14..02e0ce0 100644
--- a/src/wrappers/Element.js
+++ b/src/wrappers/Element.js
@@ -114,4 +114,4 @@
   // that reflect attributes.
   scope.matchesName = matchesName;
   scope.wrappers.Element = Element;
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/HTMLAudioElement.js b/src/wrappers/HTMLAudioElement.js
index 3b4f375..6fe73d3 100644
--- a/src/wrappers/HTMLAudioElement.js
+++ b/src/wrappers/HTMLAudioElement.js
@@ -39,4 +39,4 @@
 
   scope.wrappers.HTMLAudioElement = HTMLAudioElement;
   scope.wrappers.Audio = Audio;
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/HTMLCanvasElement.js b/src/wrappers/HTMLCanvasElement.js
index ca90a4b..63e3556 100644
--- a/src/wrappers/HTMLCanvasElement.js
+++ b/src/wrappers/HTMLCanvasElement.js
@@ -28,4 +28,4 @@
                   document.createElement('canvas'));
 
   scope.wrappers.HTMLCanvasElement = HTMLCanvasElement;
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/HTMLContentElement.js b/src/wrappers/HTMLContentElement.js
index 898d424..c4ef3c5 100644
--- a/src/wrappers/HTMLContentElement.js
+++ b/src/wrappers/HTMLContentElement.js
@@ -38,4 +38,4 @@
     registerWrapper(OriginalHTMLContentElement, HTMLContentElement);
 
   scope.wrappers.HTMLContentElement = HTMLContentElement;
-})(this.ShadowDOMPolyfill);
\ No newline at end of file
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/HTMLElement.js b/src/wrappers/HTMLElement.js
index 4dff036..1bae2cc 100644
--- a/src/wrappers/HTMLElement.js
+++ b/src/wrappers/HTMLElement.js
@@ -197,4 +197,4 @@
   // TODO: Find a better way to share these two with WrapperShadowRoot.
   scope.getInnerHTML = getInnerHTML;
   scope.setInnerHTML = setInnerHTML
-})(this.ShadowDOMPolyfill);
\ No newline at end of file
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/HTMLImageElement.js b/src/wrappers/HTMLImageElement.js
index f85a009..b6be685 100644
--- a/src/wrappers/HTMLImageElement.js
+++ b/src/wrappers/HTMLImageElement.js
@@ -40,4 +40,4 @@
 
   scope.wrappers.HTMLImageElement = HTMLImageElement;
   scope.wrappers.Image = Image;
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/HTMLMediaElement.js b/src/wrappers/HTMLMediaElement.js
index 325b080..141c84c 100644
--- a/src/wrappers/HTMLMediaElement.js
+++ b/src/wrappers/HTMLMediaElement.js
@@ -19,4 +19,4 @@
                   document.createElement('audio'));
 
   scope.wrappers.HTMLMediaElement = HTMLMediaElement;
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/HTMLOptionElement.js b/src/wrappers/HTMLOptionElement.js
index cee1cfc..ea7a751 100644
--- a/src/wrappers/HTMLOptionElement.js
+++ b/src/wrappers/HTMLOptionElement.js
@@ -60,4 +60,4 @@
 
   scope.wrappers.HTMLOptionElement = HTMLOptionElement;
   scope.wrappers.Option = Option;
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/HTMLShadowElement.js b/src/wrappers/HTMLShadowElement.js
index 9f6b761..2116ed5 100644
--- a/src/wrappers/HTMLShadowElement.js
+++ b/src/wrappers/HTMLShadowElement.js
@@ -23,4 +23,4 @@
     registerWrapper(OriginalHTMLShadowElement, HTMLShadowElement);
 
   scope.wrappers.HTMLShadowElement = HTMLShadowElement;
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/HTMLTemplateElement.js b/src/wrappers/HTMLTemplateElement.js
index 52fef46..e218aa3 100644
--- a/src/wrappers/HTMLTemplateElement.js
+++ b/src/wrappers/HTMLTemplateElement.js
@@ -81,4 +81,4 @@
     registerWrapper(OriginalHTMLTemplateElement, HTMLTemplateElement);
 
   scope.wrappers.HTMLTemplateElement = HTMLTemplateElement;
-})(this.ShadowDOMPolyfill);
\ No newline at end of file
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/HTMLUnknownElement.js b/src/wrappers/HTMLUnknownElement.js
index fe76f98..79c16e8 100644
--- a/src/wrappers/HTMLUnknownElement.js
+++ b/src/wrappers/HTMLUnknownElement.js
@@ -28,4 +28,4 @@
   HTMLUnknownElement.prototype = Object.create(HTMLElement.prototype);
   registerWrapper(OriginalHTMLUnknownElement, HTMLUnknownElement);
   scope.wrappers.HTMLUnknownElement = HTMLUnknownElement;
-})(this.ShadowDOMPolyfill);
\ No newline at end of file
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/MutationObserver.js b/src/wrappers/MutationObserver.js
index cdd667d..ee10d95 100644
--- a/src/wrappers/MutationObserver.js
+++ b/src/wrappers/MutationObserver.js
@@ -84,4 +84,4 @@
   scope.wrappers.MutationObserver = MutationObserver;
   scope.wrappers.MutationRecord = MutationRecord;
 
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/Node.js b/src/wrappers/Node.js
index 96c5fdf..55d981d 100644
--- a/src/wrappers/Node.js
+++ b/src/wrappers/Node.js
@@ -524,4 +524,4 @@
 
   scope.wrappers.Node = Node;
 
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/NodeList.js b/src/wrappers/NodeList.js
index 16baf68..83cb21b 100644
--- a/src/wrappers/NodeList.js
+++ b/src/wrappers/NodeList.js
@@ -43,4 +43,4 @@
   scope.addWrapNodeListMethod = addWrapNodeListMethod;
   scope.wrapNodeList = wrapNodeList;
 
-})(this.ShadowDOMPolyfill);
\ No newline at end of file
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/Range.js b/src/wrappers/Range.js
index d084638..6de7971 100644
--- a/src/wrappers/Range.js
+++ b/src/wrappers/Range.js
@@ -89,4 +89,4 @@
 
   scope.wrappers.Range = Range;
 
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/ShadowRoot.js b/src/wrappers/ShadowRoot.js
index 899ef98..24416b1 100644
--- a/src/wrappers/ShadowRoot.js
+++ b/src/wrappers/ShadowRoot.js
@@ -61,4 +61,5 @@
   });
 
   scope.wrappers.ShadowRoot = ShadowRoot;
-})(this.ShadowDOMPolyfill);
\ No newline at end of file
+
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/WebGLRenderingContext.js b/src/wrappers/WebGLRenderingContext.js
index 6180284..55488fc 100644
--- a/src/wrappers/WebGLRenderingContext.js
+++ b/src/wrappers/WebGLRenderingContext.js
@@ -39,4 +39,4 @@
   registerWrapper(OriginalWebGLRenderingContext, WebGLRenderingContext);
 
   scope.wrappers.WebGLRenderingContext = WebGLRenderingContext;
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/Window.js b/src/wrappers/Window.js
index 2c00323..588cb1d 100644
--- a/src/wrappers/Window.js
+++ b/src/wrappers/Window.js
@@ -46,4 +46,4 @@
 
   scope.wrappers.Window = Window;
 
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/elements-with-form-property.js b/src/wrappers/elements-with-form-property.js
index b07778e..c735591 100644
--- a/src/wrappers/elements-with-form-property.js
+++ b/src/wrappers/elements-with-form-property.js
@@ -51,4 +51,4 @@
 
   elementsWithFormProperty.forEach(createWrapperConstructor);
 
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/events.js b/src/wrappers/events.js
index b6669cf..032f6a8 100644
--- a/src/wrappers/events.js
+++ b/src/wrappers/events.js
@@ -744,4 +744,4 @@
   scope.wrappers.MutationEvent = MutationEvent;
   scope.wrappers.UIEvent = UIEvent;
 
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/generic.js b/src/wrappers/generic.js
index 89d96e8..bb0b3c6 100644
--- a/src/wrappers/generic.js
+++ b/src/wrappers/generic.js
@@ -23,4 +23,4 @@
   scope.wrappers.DocumentFragment = DocumentFragment;
   scope.wrappers.Text = Text;
 
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/node-interfaces.js b/src/wrappers/node-interfaces.js
index e606dd1..d0b174f 100644
--- a/src/wrappers/node-interfaces.js
+++ b/src/wrappers/node-interfaces.js
@@ -66,4 +66,4 @@
   scope.ChildNodeInterface = ChildNodeInterface;
   scope.ParentNodeInterface = ParentNodeInterface;
 
-})(this.ShadowDOMPolyfill);
+})(window.ShadowDOMPolyfill);
diff --git a/src/wrappers/override-constructors.js b/src/wrappers/override-constructors.js
index 18f88fc..7f7c603 100644
--- a/src/wrappers/override-constructors.js
+++ b/src/wrappers/override-constructors.js
@@ -98,4 +98,4 @@
   // Export for testing.
   scope.knownElements = elements;
 
-})(this.ShadowDOMPolyfill);
\ No newline at end of file
+})(window.ShadowDOMPolyfill);