diff --git a/src/observable/BaseObservableCollection.js b/src/observable/BaseObservableCollection.js
index 87e7c77b..13b059ae 100644
--- a/src/observable/BaseObservableCollection.js
+++ b/src/observable/BaseObservableCollection.js
@@ -18,7 +18,7 @@ export default class BaseObservableCollection {
         }
         return () => {
             if (handler) {
-                this._handlers.delete(this._handler);
+                this._handlers.delete(handler);
                 if (this._handlers.size === 0) {
                     this.onUnsubscribeLast();
                 }