diff --git a/lib/OpenLayers/Icon.js b/lib/OpenLayers/Icon.js
index 28584930e3..5d48781d2a 100644
--- a/lib/OpenLayers/Icon.js
+++ b/lib/OpenLayers/Icon.js
@@ -40,7 +40,7 @@ OpenLayers.Icon.prototype = {
     initialize: function(url, size, offset, calculateOffset) {
         this.url = url;
         this.size = (size) ? size : new OpenLayers.Size(20,20);
-        this.offset = offset ? offset : new OpenLayers.Pixel(-(size.w/2), -(size.h/2));
+        this.offset = offset ? offset : new OpenLayers.Pixel(-(this.size.w/2), -(this.size.h/2));
         this.calculateOffset = calculateOffset;
 
         var id = OpenLayers.Util.createUniqueID("OL_Icon_");