diff --git a/lib/OpenLayers/Layer/OSM.js b/lib/OpenLayers/Layer/OSM.js
index 320c4540ef..a1874e3453 100644
--- a/lib/OpenLayers/Layer/OSM.js
+++ b/lib/OpenLayers/Layer/OSM.js
@@ -5,6 +5,7 @@
 
 /**
  * @requires OpenLayers/Layer/XYZ.js
+ * @requires OpenLayers/Layer/SphericalMercator.js
  */
 
 /**