diff --git a/src/observable/list/MappedList.js b/src/observable/list/MappedList.js
index 6d5f87eb..75c220fa 100644
--- a/src/observable/list/MappedList.js
+++ b/src/observable/list/MappedList.js
@@ -32,7 +32,7 @@ export default class MappedList extends BaseObservableList {
     onUpdate(index, value, params) {
         const mappedValue = this._mappedValues[index];
         if (this._updater) {
-            this._updater(mappedValue, value);
+            this._updater(mappedValue, params, value);
         }
         this.emitUpdate(index, mappedValue, params);
     }