diff --git a/lib/OpenLayers/Layer/ArcIMS.js b/lib/OpenLayers/Layer/ArcIMS.js
index 860cd8d770..eb7dbc983c 100644
--- a/lib/OpenLayers/Layer/ArcIMS.js
+++ b/lib/OpenLayers/Layer/ArcIMS.js
@@ -205,12 +205,10 @@ OpenLayers.Layer.ArcIMS = OpenLayers.Class(OpenLayers.Layer.Grid, {
      * Parameters:
      * bounds - {<OpenLayers.Bounds>} A bounds representing the bbox for the
      *     request.
-     * scope - {Object} The scope of the callback method.
-     * prop - {String} The name of the property in the scoped object to 
-     *     recieve the image url.
      * callback - {Function} Function to call when image url is retrieved.
+     * scope - {Object} The scope of the callback method.
      */
-    getURLasync: function(bounds, scope, prop, callback) {
+    getURLasync: function(bounds, callback, scope) {
         bounds = this.adjustBounds(bounds);
         
         // create an arcxml request to generate the image
@@ -239,11 +237,7 @@ OpenLayers.Layer.ArcIMS = OpenLayers.Class(OpenLayers.Layer.Grid, {
                 var axlResp = new OpenLayers.Format.ArcXML();
                 var arcxml = axlResp.read(doc);
                 
-                scope[prop] = this.getUrlOrImage(arcxml.image.output);
-
-                // call the callback function to recieve the updated property on the
-                // scoped object
-                callback.apply(scope);
+                callback.call(scope, this.getUrlOrImage(arcxml.image.output));
             },
             scope: this
         });
diff --git a/lib/OpenLayers/Tile/Image.js b/lib/OpenLayers/Tile/Image.js
index d863d7dece..23a7c9668a 100644
--- a/lib/OpenLayers/Tile/Image.js
+++ b/lib/OpenLayers/Tile/Image.js
@@ -168,15 +168,14 @@ OpenLayers.Tile.Image = OpenLayers.Class(OpenLayers.Tile, {
         this.layer.div.appendChild(this.getTile());
         if (this.layer.async) {
             // Asynchronous image requests call the asynchronous getURL method
-            // on the layer to fetch an image that covers 'this.bounds', in the scope of
-            // 'this', setting the 'url' property of the layer itself, and running
-            // the callback 'initImage' when the image request returns.
-            var myId = this.asyncRequestId = (this.asyncRequestId || 0) + 1;
-            this.layer.getURLasync(this.bounds, this, "url", function() {
-                if (myId == this.asyncRequestId) {
+            // on the layer to fetch an image that covers 'this.bounds'.
+            var id = this.asyncRequestId = (this.asyncRequestId || 0) + 1;
+            this.layer.getURLasync(this.bounds, function(url) {
+                if (id == this.asyncRequestId) {
+                    this.url = url;
                     this.initImage();
                 }
-            });
+            }, this);
         } else {
             // synchronous image requests get the url immediately.
             this.url = this.layer.getURL(this.bounds);
diff --git a/notes/2.12.md b/notes/2.12.md
index ee5ae8843c..a02c465a7a 100644
--- a/notes/2.12.md
+++ b/notes/2.12.md
@@ -86,6 +86,10 @@ If you were previously using the `OpenLayers.Layer.SphericalMercator.forwardMerc
 
 `OpenLayers.Protocol.HTTP` no longer requires `OpenLayers.Format.QueryStringFilter`. It you need this, make sure it is included in your build config file.
 
+## Changes in getURLasync
+
+The internal `OpenLayers.Layer.getURLasync` function now take a bound, a callback and a scope. The function no longer needs update the passed property but simply to return to url.
+
 ## Deprecated Components
 
 A number of properties, methods, and constructors have been marked as deprecated for multiple releases in the 2.x series.  For the 2.12 release this deprecated functionality has been moved to a separate deprecated.js file.  If you use any of the constructors or methods below, you will have to explicitly include the deprecated.js file in your build (or add it in a separate `<script>` tag after OpenLayers.js).
diff --git a/tests/Tile/Image.html b/tests/Tile/Image.html
index 9b00113eea..0d67cf1408 100644
--- a/tests/Tile/Image.html
+++ b/tests/Tile/Image.html
@@ -85,9 +85,8 @@
         var layer = new OpenLayers.Layer.WMS(
             "Name",
             "http://labs.metacarta.com/TESTURL?",
-            {layers: 'basic'}, {async: true, getURLasync: function(bounds, scope, url, callback) {
-                scope.url = this.getURL(bounds);
-                callback.call(scope);
+            {layers: 'basic'}, {async: true, getURLasync: function(bounds, callback) {
+                callback(this.getURL(bounds));
             }}
         ); 
         map.addLayer(layer);