diff --git a/src/ol/source/debugtilesource.js b/src/ol/source/debugtilesource.js
index 08109816d6..999bd81b69 100644
--- a/src/ol/source/debugtilesource.js
+++ b/src/ol/source/debugtilesource.js
@@ -74,6 +74,13 @@ ol.DebugTile_.prototype.getImage = function(opt_context) {
 
 
 /**
+ * @classdesc
+ * A pseudo tile source, which does not fetch tiles from a server, but renders
+ * a grid outline for the tile grid/projection along with the coordinates for
+ * each tile. See examples/canvas-tiles for an example.
+ *
+ * Uses Canvas context2d, so requires Canvas support.
+ *
  * @constructor
  * @extends {ol.source.Tile}
  * @param {olx.source.TileDebugOptions} options Debug tile options.