diff --git a/src/domain/session/room/timeline/TilesCollection.js b/src/domain/session/room/timeline/TilesCollection.js
index 497c0b0d..b3696fad 100644
--- a/src/domain/session/room/timeline/TilesCollection.js
+++ b/src/domain/session/room/timeline/TilesCollection.js
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {BaseObservableList} from "../../../../observable/list/BaseObservableList.js";
+import {BaseObservableList} from "../../../../observable/list/BaseObservableList";
 import {sortedIndex} from "../../../../utils/sortedIndex.js";
 
 // maps 1..n entries to 0..1 tile. Entries are what is stored in the timeline, either an event or fragmentboundary
diff --git a/src/observable/list/BaseMappedList.js b/src/observable/list/BaseMappedList.js
index 1ccd4e12..19c98b88 100644
--- a/src/observable/list/BaseMappedList.js
+++ b/src/observable/list/BaseMappedList.js
@@ -15,7 +15,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {BaseObservableList} from "./BaseObservableList.js";
+import {BaseObservableList} from "./BaseObservableList";
 import {findAndUpdateInArray} from "./common.js";
 
 export class BaseMappedList extends BaseObservableList {
diff --git a/src/observable/list/BaseObservableList.js b/src/observable/list/BaseObservableList.ts
similarity index 100%
rename from src/observable/list/BaseObservableList.js
rename to src/observable/list/BaseObservableList.ts
diff --git a/src/observable/list/ConcatList.js b/src/observable/list/ConcatList.js
index d395e807..e87ccb60 100644
--- a/src/observable/list/ConcatList.js
+++ b/src/observable/list/ConcatList.js
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {BaseObservableList} from "./BaseObservableList.js";
+import {BaseObservableList} from "./BaseObservableList";
 
 export class ConcatList extends BaseObservableList {
     constructor(...sourceLists) {
diff --git a/src/observable/list/MappedList.js b/src/observable/list/MappedList.js
index 096a018f..dbd64921 100644
--- a/src/observable/list/MappedList.js
+++ b/src/observable/list/MappedList.js
@@ -57,7 +57,7 @@ export class MappedList extends BaseMappedList {
 }
 
 import {ObservableArray} from "./ObservableArray.js";
-import {BaseObservableList} from "./BaseObservableList.js";
+import {BaseObservableList} from "./BaseObservableList";
 
 export async function tests() {
     class MockList extends BaseObservableList {
diff --git a/src/observable/list/ObservableArray.js b/src/observable/list/ObservableArray.js
index 0f9ee99d..5d9f5c12 100644
--- a/src/observable/list/ObservableArray.js
+++ b/src/observable/list/ObservableArray.js
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {BaseObservableList} from "./BaseObservableList.js";
+import {BaseObservableList} from "./BaseObservableList";
 
 export class ObservableArray extends BaseObservableList {
     constructor(initialValues = []) {
diff --git a/src/observable/list/SortedArray.js b/src/observable/list/SortedArray.js
index 323cf776..29e0c3f1 100644
--- a/src/observable/list/SortedArray.js
+++ b/src/observable/list/SortedArray.js
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {BaseObservableList} from "./BaseObservableList.js";
+import {BaseObservableList} from "./BaseObservableList";
 import {sortedIndex} from "../../utils/sortedIndex.js";
 import {findAndUpdateInArray} from "./common.js";
 
diff --git a/src/observable/list/SortedMapList.js b/src/observable/list/SortedMapList.js
index babf5c35..2421419e 100644
--- a/src/observable/list/SortedMapList.js
+++ b/src/observable/list/SortedMapList.js
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {BaseObservableList} from "./BaseObservableList.js";
+import {BaseObservableList} from "./BaseObservableList";
 import {sortedIndex} from "../../utils/sortedIndex.js";
 
 /*
diff --git a/src/platform/web/ui/general/ListView.ts b/src/platform/web/ui/general/ListView.ts
index cdfdbf76..c3ac49a4 100644
--- a/src/platform/web/ui/general/ListView.ts
+++ b/src/platform/web/ui/general/ListView.ts
@@ -16,7 +16,7 @@ limitations under the License.
 
 import {el} from "./html";
 import {mountView, insertAt} from "./utils";
-import {BaseObservableList as ObservableList} from "../../../../observable/list/BaseObservableList.js";
+import {BaseObservableList as ObservableList} from "../../../../observable/list/BaseObservableList";
 import {IView, IMountArgs} from "./types";
 
 interface IOptions<T, V> {
diff --git a/src/platform/web/ui/session/room/TimelineView.ts b/src/platform/web/ui/session/room/TimelineView.ts
index a4e143aa..23cf0aac 100644
--- a/src/platform/web/ui/session/room/TimelineView.ts
+++ b/src/platform/web/ui/session/room/TimelineView.ts
@@ -26,7 +26,7 @@ import {MissingAttachmentView} from "./timeline/MissingAttachmentView.js";
 import {AnnouncementView} from "./timeline/AnnouncementView.js";
 import {RedactedView} from "./timeline/RedactedView.js";
 import {SimpleTile} from "../../../../../domain/session/room/timeline/tiles/SimpleTile.js";
-import {BaseObservableList as ObservableList} from "../../../../../observable/list/BaseObservableList.js";
+import {BaseObservableList as ObservableList} from "../../../../../observable/list/BaseObservableList";
 
 //import {TimelineViewModel} from "../../../../../domain/session/room/timeline/TimelineViewModel.js";
 export interface TimelineViewModel extends IObservableValue {