diff --git a/lib/OpenLayers/Layer/Grid.js b/lib/OpenLayers/Layer/Grid.js
index b4c91d40ef..f5be57fb87 100644
--- a/lib/OpenLayers/Layer/Grid.js
+++ b/lib/OpenLayers/Layer/Grid.js
@@ -65,6 +65,7 @@ OpenLayers.Layer.Grid.prototype =
         }
         
         // copy/set any non-init, non-simple values here
+        obj.tileSize = this.tileSize.copyOf();
         
         //get all additions from superclasses
         return OpenLayers.Layer.HTTPRequest.prototype.clone.apply(this, [obj]);