diff --git a/src/ol/source/imagetilesource.js b/src/ol/source/imagetilesource.js
index 453dd29126..87e8ad0f51 100644
--- a/src/ol/source/imagetilesource.js
+++ b/src/ol/source/imagetilesource.js
@@ -108,6 +108,16 @@ ol.source.TileImage.prototype.getTile = function(z, x, y, projection) {
 };
 
 
+/**
+ * @param {ol.TileUrlFunctionType} tileUrlFunction Tile URL function.
+ */
+ol.source.TileImage.prototype.setTileUrlFunction = function(tileUrlFunction) {
+  this.tileCache_.clear();
+  this.tileUrlFunction = tileUrlFunction;
+  this.dispatchChangeEvent();
+};
+
+
 /**
  * @inheritDoc
  */