Index: src/django_gheat/wlheatmap/templates/js/LayerBase.js
===================================================================
--- src/django_gheat/wlheatmap/templates/js/LayerBase.js	(revision 9599)
+++ src/django_gheat/wlheatmap/templates/js/LayerBase.js	(revision 9641)
@@ -22,7 +22,5 @@
     if (this.src.match(/^http:\/\/[abc]\.[a-z]+\.openstreetmap\.org\//)) {
         this.src = OpenLayers.Util.OSM.MISSING_TILE_URL;
-    } else if (this.src.match(/^http:\/\/[def]\.tah\.openstreetmap\.org\//)) {
-        // do nothing - this layer is transparent
-    } else {
+    } if (this.src.match(/^http:\/\/[def]\.tah\.openstreetmap\.org\//) == null) {
         OpenLayers.Util.OSM.originalOnImageLoadError;
     }