diff --git a/public/javascripts/map.js b/public/javascripts/map.js
index a48e71077..4816f762b 100644
--- a/public/javascripts/map.js
+++ b/public/javascripts/map.js
@@ -41,7 +41,7 @@ function getTileURL(bounds) {
 
    if (y < 0 || y >= limit)
    {
-     return null;
+     return OpenLayers.Util.getImagesLocation() + "404.png";
    }
    else
    {