diff --git a/src/PointerEvent.js b/src/PointerEvent.js
index f1896c99..79d9eeb8 100644
--- a/src/PointerEvent.js
+++ b/src/PointerEvent.js
@@ -29,6 +29,40 @@
   } catch(e) {
   }
 
+  var MOUSE_PROPS = [
+    'bubbles',
+    'cancelable',
+    'view',
+    'detail',
+    'screenX',
+    'screenY',
+    'clientX',
+    'clientY',
+    'ctrlKey',
+    'altKey',
+    'shiftKey',
+    'metaKey',
+    'button',
+    'relatedTarget',
+  ];
+
+  var MOUSE_DEFAULTS = [
+    false,
+    false,
+    null,
+    null,
+    0,
+    0,
+    0,
+    0,
+    false,
+    false,
+    false,
+    false,
+    0,
+    null
+  ];
+
   function PointerEvent(inType, inDict) {
     inDict = inDict || {};
     // According to the w3c spec,
@@ -67,29 +101,13 @@
       e = new MouseEvent(inType, inDict);
     } else {
       e = document.createEvent('MouseEvent');
-      // import values from the given dictionary
-      var props = {
-        bubbles: false,
-        cancelable: false,
-        view: null,
-        detail: null,
-        screenX: 0,
-        screenY: 0,
-        clientX: 0,
-        clientY: 0,
-        ctrlKey: false,
-        altKey: false,
-        shiftKey: false,
-        metaKey: false,
-        button: 0,
-        relatedTarget: null
-      };
 
-      Object.keys(props).forEach(function(k) {
-        if (k in inDict) {
-          props[k] = inDict[k];
-        }
-      });
+      // import values from the given dictionary
+      var props = {}, p;
+      for(var i = 0; i < MOUSE_PROPS.length; i++) {
+        p = MOUSE_PROPS[i];
+        props[p] = inDict[p] || MOUSE_DEFAULTS[i];
+      }
 
       // define the properties inherited from MouseEvent
       e.initMouseEvent(
diff --git a/src/dispatcher.js b/src/dispatcher.js
index d80608a5..442f51a3 100644
--- a/src/dispatcher.js
+++ b/src/dispatcher.js
@@ -5,6 +5,73 @@
  */
 
 (function(scope) {
+  var CLONE_PROPS = [
+    // MouseEvent
+    'bubbles',
+    'cancelable',
+    'view',
+    'detail',
+    'screenX',
+    'screenY',
+    'clientX',
+    'clientY',
+    'ctrlKey',
+    'altKey',
+    'shiftKey',
+    'metaKey',
+    'button',
+    'relatedTarget',
+    // DOM Level 3
+    'buttons',
+    // PointerEvent
+    'pointerId',
+    'width',
+    'height',
+    'pressure',
+    'tiltX',
+    'tiltY',
+    'pointerType',
+    'hwTimestamp',
+    'isPrimary',
+    // event instance
+    'type',
+    'target',
+    'currentTarget'
+  ];
+
+  var CLONE_DEFAULTS = [
+    // MouseEvent
+    false,
+    false,
+    null,
+    null,
+    0,
+    0,
+    0,
+    0,
+    false,
+    false,
+    false,
+    false,
+    0,
+    null,
+    // DOM Level 3
+    0,
+    // PointerEvent
+    0,
+    0,
+    0,
+    0,
+    0,
+    0,
+    '',
+    0,
+    false,
+    // event instance
+    '',
+    null,
+    null
+  ];
 
   /**
    * This module is for normalizing events. Mouse and Touch events will be
@@ -19,9 +86,9 @@
    *   - pointercancel: a pointer will no longer generate events
    */
   var dispatcher = {
-    targets: new SideTable,
-    handledEvents: new SideTable,
-    pointermap: new scope.PointerMap,
+    targets: new SideTable(),
+    handledEvents: new SideTable(),
+    pointermap: new scope.PointerMap(),
     eventMap: {},
     // Scope objects for native events.
     // This exists for ease of testing.
@@ -163,9 +230,10 @@
      *    properties.
      */
     cloneEvent: function(inEvent) {
-      var eventCopy = {};
-      for (var n in inEvent) {
-        eventCopy[n] = inEvent[n];
+      var eventCopy = {}, p;
+      for (var i = 0; i < CLONE_PROPS.length; i++) {
+        p = CLONE_PROPS[i];
+        eventCopy[p] = inEvent[p] || CLONE_DEFAULTS[i];
       }
       return eventCopy;
     },