diff --git a/src/ol/canvas/canvas.js b/src/ol/canvas/canvas.js
index 266718953d..99bcd99217 100644
--- a/src/ol/canvas/canvas.js
+++ b/src/ol/canvas/canvas.js
@@ -9,15 +9,19 @@ goog.require('goog.dom.TagName');
  * @const
  * @type {boolean}
  */
-ol.canvas.SUPPORTED = (function() {
-  if (!('HTMLCanvasElement' in goog.global)) {
-    return false;
-  }
-  try {
-    var canvas = /** @type {HTMLCanvasElement} */
-        (goog.dom.createElement(goog.dom.TagName.CANVAS));
-    return !goog.isNull(canvas.getContext('2d'));
-  } catch (e) {
-    return false;
-  }
-})();
+ol.canvas.SUPPORTED = (
+    /**
+     * @return {boolean} Canvas supported.
+     */
+    function() {
+      if (!('HTMLCanvasElement' in goog.global)) {
+        return false;
+      }
+      try {
+        var canvas = /** @type {HTMLCanvasElement} */
+            (goog.dom.createElement(goog.dom.TagName.CANVAS));
+        return !goog.isNull(canvas.getContext('2d'));
+      } catch (e) {
+        return false;
+      }
+    })();