diff --git a/lib/OpenLayers/Map.js b/lib/OpenLayers/Map.js
index fe374d9bae..92f5a02da5 100644
--- a/lib/OpenLayers/Map.js
+++ b/lib/OpenLayers/Map.js
@@ -1833,10 +1833,14 @@ OpenLayers.Map = OpenLayers.Class({
                 var latDelta = maxExtentCenter.lat - this.center.lat;
                 var extentWidth = Math.round(maxExtent.getWidth() / res);
                 var extentHeight = Math.round(maxExtent.getHeight() / res);
-                var left = (this.size.w - extentWidth) / 2 - lonDelta / res;
-                var top = (this.size.h - extentHeight) / 2 - latDelta / res;
-                this.minPx = new OpenLayers.Pixel(left, top);
-                this.maxPx = new OpenLayers.Pixel(left + extentWidth, top + extentHeight);
+                this.minPx = {
+                    x: (this.size.w - extentWidth) / 2 - lonDelta / res,
+                    y: (this.size.h - extentHeight) / 2 - latDelta / res
+                };
+                this.maxPx = {
+                    x: this.minPx.x + Math.round(maxExtent.getWidth() / res),
+                    y: this.minPx.y + Math.round(maxExtent.getHeight() / res)
+                };
             }
 
             if (zoomChanged) {