diff --git a/lib/OpenLayers/Map.js b/lib/OpenLayers/Map.js
index 18042517fb..b23ab7c9ee 100644
--- a/lib/OpenLayers/Map.js
+++ b/lib/OpenLayers/Map.js
@@ -182,15 +182,19 @@ OpenLayers.Map.prototype = {
     * @return {OpenLayers.Bounds}
     */
     getExtent: function () {
-        var res = this.getResolution();
-        var size = this.getSize();
-        var w_deg = size.w * res;
-        var h_deg = size.h * res;
-        return new OpenLayers.Bounds(
-            this.center.lon - w_deg / 2, 
-            this.center.lat - h_deg / 2,
-            this.center.lon + w_deg / 2,
-            this.center.lat + h_deg / 2);
+        if (this.center) {
+            var res = this.getResolution();
+            var size = this.getSize();
+            var w_deg = size.w * res;
+            var h_deg = size.h * res;
+            return new OpenLayers.Bounds(
+                this.center.lon - w_deg / 2, 
+                this.center.lat - h_deg / 2,
+                this.center.lon + w_deg / 2,
+                this.center.lat + h_deg / 2);
+        } else {
+            return null;
+        }
     },
 
     /**