diff --git a/src/observable/map/MappedMap.js b/src/observable/map/MappedMap.js
index 7b7d1583..28b7d1e8 100644
--- a/src/observable/map/MappedMap.js
+++ b/src/observable/map/MappedMap.js
@@ -67,6 +67,7 @@ export class MappedMap extends BaseObservableMap {
     }
 
     onUnsubscribeLast() {
+        super.onUnsubscribeLast();
         this._subscription = this._subscription();
         this._mappedValues.clear();
     }