diff --git a/lib/OpenLayers/Layer/ArcGISCache.js b/lib/OpenLayers/Layer/ArcGISCache.js
index 9c500e4533..27173392c4 100644
--- a/lib/OpenLayers/Layer/ArcGISCache.js
+++ b/lib/OpenLayers/Layer/ArcGISCache.js
@@ -452,7 +452,9 @@ OpenLayers.Layer.ArcGISCache = OpenLayers.Class(OpenLayers.Layer.XYZ, {
         // Write the values into our formatted url
         url = OpenLayers.String.format(url, {'x': x, 'y': y, 'z': z});
 
-        return url;
+        return OpenLayers.Util.urlAppend(
+            url, OpenLayers.Util.getParameterString(this.params)
+        );
     },
 
     /**
diff --git a/lib/OpenLayers/Layer/HTTPRequest.js b/lib/OpenLayers/Layer/HTTPRequest.js
index 7855cb6b03..d1e9bf2219 100644
--- a/lib/OpenLayers/Layer/HTTPRequest.js
+++ b/lib/OpenLayers/Layer/HTTPRequest.js
@@ -60,7 +60,9 @@ OpenLayers.Layer.HTTPRequest = OpenLayers.Class(OpenLayers.Layer, {
     initialize: function(name, url, params, options) {
         OpenLayers.Layer.prototype.initialize.apply(this, [name, options]);
         this.url = url;
-        this.params = OpenLayers.Util.extend( {}, params);
+        if (!this.params) {
+            this.params = OpenLayers.Util.extend({}, params);
+        }
     },
 
     /**
diff --git a/tests/Layer/ArcGISCache.html b/tests/Layer/ArcGISCache.html
index d1ae00ed93..0b54464493 100644
--- a/tests/Layer/ArcGISCache.html
+++ b/tests/Layer/ArcGISCache.html
@@ -53,7 +53,8 @@
         //initialize the layer using the JSON object from an arcgis server
         //SEE: ArcGISCache.json
         var layer = new OpenLayers.Layer.ArcGISCache(name, url, {
-            layerInfo: layerInfo
+            layerInfo: layerInfo,
+            params: {foo: "bar"}
         });
         var map = new OpenLayers.Map('map', { 
             maxExtent: layer.maxExtent,
@@ -98,14 +99,14 @@
             }
         ];
         
-        t.plan( urlSets.length );        
+        t.plan( urlSets.length );
         for(var i=0;i<urlSets.length;i++) 
         {
             var o = urlSets[i];            
             map.zoomToExtent(o.bounds, true);
             
             var resultUrl = layer.getURL(o.bounds);            
-            t.ok( resultUrl == o.url, "correct tile returned for " + o.bounds);        
+            t.ok( resultUrl == o.url + "?foo=bar", "correct tile returned for " + o.bounds);        
         }
     }    
     
diff --git a/tests/Layer/HTTPRequest.html b/tests/Layer/HTTPRequest.html
index 6539b12bef..6ea34810e5 100644
--- a/tests/Layer/HTTPRequest.html
+++ b/tests/Layer/HTTPRequest.html
@@ -12,7 +12,7 @@
     var options = { chicken: 151, foo: "bar" };
 
     function test_Layer_HTTPRequest_constructor (t) {
-        t.plan( 5 );
+        t.plan( 6 );
 
         layer = new OpenLayers.Layer.HTTPRequest(name, url, params, options);
         
@@ -27,8 +27,11 @@
         t.ok( ((layer.params["map"] == '/mapdata/vmap_wms.map') && 
                (layer.params["layers"] == "basic") &&
                (layer.params["format"] == "image/png")), "layer.params correctly set" );
-
-
+        
+        layer = new OpenLayers.Layer.HTTPRequest(name, url, null, {params: params});
+        t.ok( ((layer.params["map"] == '/mapdata/vmap_wms.map') && 
+               (layer.params["layers"] == "basic") &&
+               (layer.params["format"] == "image/png")), "layer.params correctly set from options" );
     }
 
     function test_Layer_HTTPRequest_clone (t) {