diff --git a/lib/OpenLayers/Map.js b/lib/OpenLayers/Map.js
index 349dba9879..52a2ab4e3a 100644
--- a/lib/OpenLayers/Map.js
+++ b/lib/OpenLayers/Map.js
@@ -817,7 +817,7 @@ OpenLayers.Map.prototype = {
         var scale = null;
 
         if (this.baseLayer != null) {
-            var res = this.baseLayer.getResolution();
+            var res = this.getResolution();
             var units = this.baseLayer.units;
             scale = res * OpenLayers.INCHES_PER_UNIT[units] *
                     OpenLayers.DOTS_PER_INCH;