diff --git a/src/ol/Object.js b/src/ol/Object.js
index c1b62a1c2b..59fb349811 100644
--- a/src/ol/Object.js
+++ b/src/ol/Object.js
@@ -95,7 +95,7 @@ class BaseObject extends Observable {
 
     /**
      * @private
-     * @type {?Object<string, *>}
+     * @type {Object<string, *>}
      */
     this.values_ = null;
 
diff --git a/src/ol/events/Target.js b/src/ol/events/Target.js
index eea7c1624a..e8e4967acd 100644
--- a/src/ol/events/Target.js
+++ b/src/ol/events/Target.js
@@ -40,19 +40,19 @@ class Target extends Disposable {
 
     /**
      * @private
-     * @type {?Object<string, number>}
+     * @type {Object<string, number>}
      */
     this.pendingRemovals_ = null;
 
     /**
      * @private
-     * @type {?Object<string, number>}
+     * @type {Object<string, number>}
      */
     this.dispatching_ = null;
 
     /**
      * @private
-     * @type {?Object<string, Array<import("../events.js").Listener>>}
+     * @type {Object<string, Array<import("../events.js").Listener>>}
      */
     this.listeners_ = null;
   }