diff --git a/src/observable/index.js b/src/observable/index.js
index 27d8a7ef..8b2e5367 100644
--- a/src/observable/index.js
+++ b/src/observable/index.js
@@ -23,7 +23,7 @@ import {BaseObservableMap} from "./map/BaseObservableMap.js";
 export { ObservableArray } from "./list/ObservableArray";
 export { SortedArray } from "./list/SortedArray.js";
 export { MappedList } from "./list/MappedList.js";
-export { AsyncMappedList } from "./list/AsyncMappedList.js";
+export { AsyncMappedList } from "./list/AsyncMappedList";
 export { ConcatList } from "./list/ConcatList.js";
 export { ObservableMap } from "./map/ObservableMap.js";
 
diff --git a/src/observable/list/AsyncMappedList.js b/src/observable/list/AsyncMappedList.ts
similarity index 100%
rename from src/observable/list/AsyncMappedList.js
rename to src/observable/list/AsyncMappedList.ts