diff --git a/src/ol/typedefs.js b/src/ol/typedefs.js
index 778f2765af..6f56d9fe19 100644
--- a/src/ol/typedefs.js
+++ b/src/ol/typedefs.js
@@ -229,20 +229,6 @@ ol.DrawGeometryFunctionType;
 ol.EventsConditionType;
 
 
-/**
- * Key to use with {@link ol.Observable#unByKey}.
- *
- * @typedef {{bindTo: (Object|undefined),
- *     boundListener: (ol.EventsListenerFunctionType|undefined),
- *     callOnce: boolean,
- *     deleteIndex: (number|undefined),
- *     listener: ol.EventsListenerFunctionType,
- *     target: (EventTarget|ol.events.EventTarget),
- *     type: string}}
- */
-ol.EventsKey;
-
-
 /**
  * Listener function. This function is called with an event object as argument.
  * When the function returns `false`, event propagation will stop.
diff --git a/src/ol/types.js b/src/ol/types.js
index 0553668411..d0d8b8ae0e 100644
--- a/src/ol/types.js
+++ b/src/ol/types.js
@@ -9,3 +9,15 @@
  * @api
  */
 
+/**
+ * Key to use with {@link module:ol/Observable~Observable#unByKey}.
+ * @typedef {Object} EventsKey
+ * @property {Object} [bindTo]
+ * @property {ol.EventsListenerFunctionType} [boundListener]
+ * @property {boolean} callOnce
+ * @property {number} [deleteIndex]
+ * @property {ol.EventsListenerFunctionType} listener
+ * @property {EventTarget|ol.events.EventTarget} target
+ * @property {string} type
+ */
+