diff --git a/src/pixi/display/DisplayObject.js b/src/pixi/display/DisplayObject.js
index 76cacac..50fa1c9 100644
--- a/src/pixi/display/DisplayObject.js
+++ b/src/pixi/display/DisplayObject.js
@@ -303,15 +303,14 @@
  */
 Object.defineProperty(PIXI.DisplayObject.prototype, 'worldVisible', {
     get: function() {
-        
         var item = this;
-    
+
         do
         {
             if(!item.visible)return false;
             item = item.parent;
         }
-        while(item.parent);
+        while(item && item.parent);
 
         return true;
     }
@@ -326,11 +325,8 @@
  * @type Graphics
  */
 Object.defineProperty(PIXI.DisplayObject.prototype, 'mask', {
-   
     get: function() {
-
         return this._mask;
-    
     },
     set: function(value) {
 
@@ -368,8 +364,6 @@
 
             // TODO change this as it is legacy
             this._filterBlock = {target:this, filterPasses:passes};
-            
-           
         }
 
         this._filters = value;
@@ -453,4 +447,4 @@
 
 PIXI.EmptyRectangle = new PIXI.Rectangle(0,0,0,0);
 
-PIXI.visibleCount = 0;
\ No newline at end of file
+PIXI.visibleCount = 0;