diff --git a/src/ol/observable.js b/src/ol/observable.js
index e7a304a28b..0f48f60ea0 100644
--- a/src/ol/observable.js
+++ b/src/ol/observable.js
@@ -34,6 +34,16 @@ ol.Observable = function() {
 goog.inherits(ol.Observable, goog.events.EventTarget);
 
 
+/**
+ * Removes an event listener using the key returned by `on()` or `once()`.
+ * @param {goog.events.Key} key The key returned by `on()` or `once()`.
+ * @api stable
+ */
+ol.Observable.unByKey = function(key) {
+  goog.events.unlistenByKey(key);
+};
+
+
 /**
  * Increases the revision counter and disptches a 'change' event.
  * @fires change
@@ -95,9 +105,10 @@ ol.Observable.prototype.un = function(type, listener, opt_this) {
 
 /**
  * Removes an event listener using the key returned by `on()` or `once()`.
- * @param {goog.events.Key} key Key.
+ * Note that using the {@link ol.Observable.unByKey} static function is to
+ * be preferred.
+ * @param {goog.events.Key} key The key returned by `on()` or `once()`.
+ * @function
  * @api stable
  */
-ol.Observable.prototype.unByKey = function(key) {
-  goog.events.unlistenByKey(key);
-};
+ol.Observable.prototype.unByKey = ol.Observable.unByKey;
diff --git a/test/spec/ol/observable.test.js b/test/spec/ol/observable.test.js
index 7d7e93cbc9..890e83c842 100644
--- a/test/spec/ol/observable.test.js
+++ b/test/spec/ol/observable.test.js
@@ -144,7 +144,7 @@ describe('ol.Observable', function() {
 
   });
 
-  describe('#unByKey()', function() {
+  describe('ol.Observable.unByKey()', function() {
     var observable, listener;
     beforeEach(function() {
       observable = new ol.Observable();
@@ -157,7 +157,7 @@ describe('ol.Observable', function() {
       observable.dispatchEvent('foo');
       expect(listener.calledOnce).to.be(true);
 
-      observable.unByKey(key);
+      ol.Observable.unByKey(key);
       observable.dispatchEvent('foo');
       expect(listener.callCount).to.be(1);
     });