diff --git a/src/boot.js b/src/boot.js
index c6d552b4..f0226591 100644
--- a/src/boot.js
+++ b/src/boot.js
@@ -6,6 +6,7 @@
 
 (function(scope) {
   scope = scope || {};
+  scope.external = scope.external || {};
   var target = {
     shadow: function(inEl) {
       if (inEl) {
diff --git a/src/capture.js b/src/capture.js
index 464e7724..e07b45e5 100644
--- a/src/capture.js
+++ b/src/capture.js
@@ -32,7 +32,7 @@
       dispatcher.releaseCapture(pointerId, this);
     };
   }
-  if (!Element.prototype.setPointerCapture) {
+  if (window.Element && !Element.prototype.setPointerCapture) {
     Object.defineProperties(Element.prototype, {
       'setPointerCapture': {
         value: s
diff --git a/src/dispatcher.js b/src/dispatcher.js
index 058fcdc4..7d11d239 100644
--- a/src/dispatcher.js
+++ b/src/dispatcher.js
@@ -131,6 +131,9 @@
         es.unregister.call(es, element);
       }
     },
+    contains: scope.external.contains || function(container, contained) {
+      return container.contains(contained);
+    },
     // EVENTS
     down: function(inEvent) {
       this.fireEvent('pointerdown', inEvent);
@@ -161,13 +164,13 @@
       this.fireEvent('pointercancel', inEvent);
     },
     leaveOut: function(event) {
-      if (!event.target.contains(event.relatedTarget)) {
+      if (!this.contains(event.target, event.relatedTarget)) {
         this.leave(event);
       }
       this.out(event);
     },
     enterOver: function(event) {
-      if (!event.target.contains(event.relatedTarget)) {
+      if (!this.contains(event.target, event.relatedTarget)) {
         this.enter(event);
       }
       this.over(event);
@@ -199,10 +202,10 @@
         this.removeEvent(target, e);
       }, this);
     },
-    addEvent: function(target, eventName) {
+    addEvent: scope.external.addEvent || function(target, eventName) {
       target.addEventListener(eventName, this.boundHandler);
     },
-    removeEvent: function(target, eventName) {
+    removeEvent: scope.external.removeEvent || function(target, eventName) {
       target.removeEventListener(eventName, this.boundHandler);
     },
     // EVENT CREATION AND TRACKING
@@ -282,7 +285,7 @@
      * @param {Event} inEvent The event to be dispatched.
      * @return {Boolean} True if an event handler returns true, false otherwise.
      */
-    dispatchEvent: function(inEvent) {
+    dispatchEvent: scope.external.dispatchEvent || function(inEvent) {
       var t = this.getTarget(inEvent);
       if (t) {
         return t.dispatchEvent(inEvent);
diff --git a/src/mouse.js b/src/mouse.js
index 9601eb23..e7138b7e 100644
--- a/src/mouse.js
+++ b/src/mouse.js
@@ -94,7 +94,7 @@
       this.cleanupMouse();
     },
     cleanupMouse: function() {
-      pointermap.delete(this.POINTER_ID);
+      pointermap['delete'](this.POINTER_ID);
     }
   };
 
diff --git a/src/ms.js b/src/ms.js
index 7d0c3564..f35f888f 100644
--- a/src/ms.js
+++ b/src/ms.js
@@ -41,7 +41,7 @@
       return e;
     },
     cleanup: function(id) {
-      pointermap.delete(id);
+      pointermap['delete'](id);
     },
     MSPointerDown: function(inEvent) {
       pointermap.set(inEvent.pointerId, inEvent);
diff --git a/src/touch.js b/src/touch.js
index 0a5c45de..24768ac3 100644
--- a/src/touch.js
+++ b/src/touch.js
@@ -54,11 +54,11 @@
       }
     },
     elementRemoved: function(el) {
-      this.scrollType.delete(el);
+      this.scrollType['delete'](el);
       dispatcher.unlisten(el, this.events);
       // remove touch-action from shadow
       allShadows(el).forEach(function(s) {
-        this.scrollType.delete(s);
+        this.scrollType['delete'](s);
         dispatcher.unlisten(s, this.events);
       }, this);
     },
@@ -291,7 +291,7 @@
       this.cleanUpPointer(inPointer);
     },
     cleanUpPointer: function(inPointer) {
-      pointermap.delete(inPointer.pointerId);
+      pointermap['delete'](inPointer.pointerId);
       this.removePrimaryPointer(inPointer);
     },
     // prevent synth mouse events from creating pointer events