diff --git a/src/ol/layer/tilelayer.js b/src/ol/layer/tilelayer.js
index f8ba630d95..bb5c62e4cb 100644
--- a/src/ol/layer/tilelayer.js
+++ b/src/ol/layer/tilelayer.js
@@ -1,7 +1,6 @@
 goog.provide('ol.layer.Tile');
 
 goog.require('ol.layer.Layer');
-goog.require('ol.source.Tile');
 
 
 /**
@@ -44,14 +43,6 @@ goog.exportProperty(
     ol.layer.Tile.prototype.getPreload);
 
 
-/**
- * @return {ol.source.Tile} Source.
- */
-ol.layer.Tile.prototype.getTileSource = function() {
-  return /** @type {ol.source.Tile} */ (this.getSource());
-};
-
-
 /**
  * @param {number} preload Preload.
  * @todo stability experimental
diff --git a/src/ol/renderer/canvas/canvastilelayerrenderer.js b/src/ol/renderer/canvas/canvastilelayerrenderer.js
index eae181952b..3b7dbc7ba0 100644
--- a/src/ol/renderer/canvas/canvastilelayerrenderer.js
+++ b/src/ol/renderer/canvas/canvastilelayerrenderer.js
@@ -18,6 +18,7 @@ goog.require('ol.extent');
 goog.require('ol.layer.Tile');
 goog.require('ol.renderer.Map');
 goog.require('ol.renderer.canvas.Layer');
+goog.require('ol.source.Tile');
 
 
 
@@ -167,7 +168,8 @@ ol.renderer.canvas.TileLayer.prototype.renderFrame =
 
   var tileLayer = this.getLayer();
   goog.asserts.assertInstanceof(tileLayer, ol.layer.Tile);
-  var tileSource = tileLayer.getTileSource();
+  var tileSource = tileLayer.getSource();
+  goog.asserts.assertInstanceof(tileSource, ol.source.Tile);
   var tileGrid = tileSource.getTileGrid();
   if (goog.isNull(tileGrid)) {
     tileGrid = ol.tilegrid.getForProjection(projection);
diff --git a/src/ol/renderer/dom/domtilelayerrenderer.js b/src/ol/renderer/dom/domtilelayerrenderer.js
index af10ad9eba..58936b2248 100644
--- a/src/ol/renderer/dom/domtilelayerrenderer.js
+++ b/src/ol/renderer/dom/domtilelayerrenderer.js
@@ -20,6 +20,7 @@ goog.require('ol.dom');
 goog.require('ol.extent');
 goog.require('ol.layer.Tile');
 goog.require('ol.renderer.dom.Layer');
+goog.require('ol.source.Tile');
 goog.require('ol.tilegrid.TileGrid');
 
 
@@ -84,7 +85,8 @@ ol.renderer.dom.TileLayer.prototype.renderFrame =
 
   var tileLayer = this.getLayer();
   goog.asserts.assertInstanceof(tileLayer, ol.layer.Tile);
-  var tileSource = tileLayer.getTileSource();
+  var tileSource = tileLayer.getSource();
+  goog.asserts.assertInstanceof(tileSource, ol.source.Tile);
   var tileGrid = tileSource.getTileGrid();
   if (goog.isNull(tileGrid)) {
     tileGrid = ol.tilegrid.getForProjection(projection);
diff --git a/src/ol/renderer/webgl/webgltilelayerrenderer.js b/src/ol/renderer/webgl/webgltilelayerrenderer.js
index 7243b5d82a..64f836c862 100644
--- a/src/ol/renderer/webgl/webgltilelayerrenderer.js
+++ b/src/ol/renderer/webgl/webgltilelayerrenderer.js
@@ -17,6 +17,7 @@ goog.require('ol.layer.Tile');
 goog.require('ol.math');
 goog.require('ol.renderer.webgl.Layer');
 goog.require('ol.renderer.webgl.tilelayer.shader');
+goog.require('ol.source.Tile');
 goog.require('ol.structs.Buffer');
 
 
@@ -116,7 +117,8 @@ ol.renderer.webgl.TileLayer.prototype.renderFrame =
 
   var tileLayer = this.getLayer();
   goog.asserts.assertInstanceof(tileLayer, ol.layer.Tile);
-  var tileSource = tileLayer.getTileSource();
+  var tileSource = tileLayer.getSource();
+  goog.asserts.assertInstanceof(tileSource, ol.source.Tile);
   var tileGrid = tileSource.getTileGrid();
   if (goog.isNull(tileGrid)) {
     tileGrid = ol.tilegrid.getForProjection(projection);