diff --git a/externs/olx.js b/externs/olx.js
index 279396a59a..8669a9ad4d 100644
--- a/externs/olx.js
+++ b/externs/olx.js
@@ -3599,7 +3599,7 @@ olx.source.TileImageOptions.prototype.state;
 
 
 /**
- * tile class
+ * Class used to instantiate image tiles. Default is {@link ol.ImageTile}.
  * @type {function(new: ol.ImageTile, ol.TileCoord,
  *                 ol.TileState, string, ?string,
  *                 ol.TileLoadFunctionType)|undefined}
@@ -4996,7 +4996,10 @@ olx.source.StaticVectorOptions.prototype.urls;
  *     url: (string|undefined),
  *     maxZoom: (number|undefined),
  *     tileLoadFunction: (ol.TileLoadFunctionType|undefined),
- *     urls: (Array.<string>|undefined)}}
+ *     urls: (Array.<string>|undefined),
+ *     tileClass: (function(new: ol.ImageTile, ol.TileCoord,
+ *                          ol.TileState, string, ?string,
+ *                          ol.TileLoadFunctionType)|undefined)}}
  * @api
  */
 olx.source.WMTSOptions;
@@ -5066,6 +5069,16 @@ olx.source.WMTSOptions.prototype.layer;
 olx.source.WMTSOptions.prototype.style;
 
 
+/**
+ * Class used to instantiate image tiles. Default is {@link ol.ImageTile}.
+ * @type {function(new: ol.ImageTile, ol.TileCoord,
+ *                 ol.TileState, string, ?string,
+ *                 ol.TileLoadFunctionType)|undefined}
+ * @api
+ */
+olx.source.WMTSOptions.prototype.tileClass;
+
+
 /**
  * The pixel ratio used by the tile service. For example, if the tile
  * service advertizes 256px by 256px tiles but actually sends 512px
diff --git a/src/ol/source/wmtssource.js b/src/ol/source/wmtssource.js
index 4b66dfd216..0d37688c8c 100644
--- a/src/ol/source/wmtssource.js
+++ b/src/ol/source/wmtssource.js
@@ -181,6 +181,7 @@ ol.source.WMTS = function(options) {
     crossOrigin: options.crossOrigin,
     logo: options.logo,
     projection: options.projection,
+    tileClass: options.tileClass,
     tileGrid: tileGrid,
     tileLoadFunction: options.tileLoadFunction,
     tilePixelRatio: options.tilePixelRatio,