diff --git a/src/ol/structs/rbush.js b/src/ol/structs/rbush.js
index 4de21cbc1f..a9c5cce5d9 100644
--- a/src/ol/structs/rbush.js
+++ b/src/ol/structs/rbush.js
@@ -228,7 +228,7 @@ ol.structs.RBush.prototype.isEmpty = function() {
  */
 ol.structs.RBush.prototype.clear = function() {
   this.rbush_.clear();
-  goog.object.clear(this.items_);
+  this.items_ = {};
 };