diff --git a/lib/OpenLayers/Map.js b/lib/OpenLayers/Map.js
index abf3328a8c..bd8378a10b 100644
--- a/lib/OpenLayers/Map.js
+++ b/lib/OpenLayers/Map.js
@@ -1664,7 +1664,7 @@ OpenLayers.Map = OpenLayers.Class({
             }
 
             if (zoomChanged) {
-                this.zoom = zoom;
+                this.zoom = parseInt(zoom);
                 this.resolution = this.getResolutionForZoom(zoom);
                 // zoom level has changed, increment viewRequestID.
                 this.viewRequestID++;