diff --git a/src/ol/render/canvas/canvas.js b/src/ol/render/canvas/canvas.js
index 3b79a6fd3f..fdf805afb6 100644
--- a/src/ol/render/canvas/canvas.js
+++ b/src/ol/render/canvas/canvas.js
@@ -3,6 +3,12 @@ goog.provide('ol.render.canvas');
 goog.require('ol.color');
 
 
+/**
+ * @typedef {{fillStyle: string}}
+ */
+ol.render.canvas.FillState;
+
+
 /**
  * @const
  * @type {string}