diff --git a/plugins/layer_types/openlayers_layer_type_xyz.js b/plugins/layer_types/openlayers_layer_type_xyz.js
index e2f28f6..b431c7c 100644
--- a/plugins/layer_types/openlayers_layer_type_xyz.js
+++ b/plugins/layer_types/openlayers_layer_type_xyz.js
@@ -31,6 +31,26 @@ Drupal.openlayers.layer.xyz = function(title, map, options) {
     options.wrapDateLine = null;
   }
 
+  options.getURL = function (bounds) {
+    var xyz = this.getXYZ(bounds);
+
+    // Fixed the -1 zoom level error in openlayers 2.11.
+    var res = this.map.getResolution();
+    var resolutions = this.serverResolutions || this.resolutions;
+    var z = this.zoomOffset == 0 ?
+            (OpenLayers.Util.indexOf(resolutions, res) != -1 ? OpenLayers.Util.indexOf(resolutions, res) : this.map.getZoom() + this.zoomOffset) :
+            this.map.getZoom() + this.zoomOffset;
+    xyz.z = z;
+
+    var url = this.url;
+    if (OpenLayers.Util.isArray(url)) {
+        var s = '' + xyz.x + xyz.y + xyz.z;
+        url = this.selectUrl(s, url);
+    }
+
+    return OpenLayers.String.format(url, xyz);
+  }
+
   var layer = new OpenLayers.Layer.XYZ(title, options.url, options);
   layer.styleMap = styleMap;
   return layer;