diff --git a/src/domain/navigation/Navigation.js b/src/domain/navigation/Navigation.js
index 3167475f..340ae0d5 100644
--- a/src/domain/navigation/Navigation.js
+++ b/src/domain/navigation/Navigation.js
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {BaseObservableValue, ObservableValue} from "../../observable/ObservableValue.js";
+import {BaseObservableValue, ObservableValue} from "../../observable/ObservableValue";
 
 export class Navigation {
     constructor(allowsChild) {
diff --git a/src/domain/session/RoomGridViewModel.js b/src/domain/session/RoomGridViewModel.js
index 08887f3e..d89d821a 100644
--- a/src/domain/session/RoomGridViewModel.js
+++ b/src/domain/session/RoomGridViewModel.js
@@ -186,7 +186,7 @@ export class RoomGridViewModel extends ViewModel {
 }
 
 import {createNavigation} from "../navigation/index.js";
-import {ObservableValue} from "../../observable/ObservableValue.js";
+import {ObservableValue} from "../../observable/ObservableValue";
 
 export function tests() { 
     class RoomVMMock {
diff --git a/src/domain/session/RoomViewModelObservable.js b/src/domain/session/RoomViewModelObservable.js
index b9549905..2a706045 100644
--- a/src/domain/session/RoomViewModelObservable.js
+++ b/src/domain/session/RoomViewModelObservable.js
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {ObservableValue} from "../../observable/ObservableValue.js";
+import {ObservableValue} from "../../observable/ObservableValue";
 
 /**
 Depending on the status of a room (invited, joined, archived, or none),
@@ -77,4 +77,4 @@ export class RoomViewModelObservable extends ObservableValue {
         this.unsubscribeAll();
         this.get()?.dispose();
     }
-}
\ No newline at end of file
+}
diff --git a/src/domain/session/room/timeline/ReactionsViewModel.js b/src/domain/session/room/timeline/ReactionsViewModel.js
index ca5d43f0..25d74b49 100644
--- a/src/domain/session/room/timeline/ReactionsViewModel.js
+++ b/src/domain/session/room/timeline/ReactionsViewModel.js
@@ -189,7 +189,7 @@ import {HomeServer as MockHomeServer} from "../../../../mocks/HomeServer.js";
 // other imports
 import {BaseMessageTile} from "./tiles/BaseMessageTile.js";
 import {MappedList} from "../../../../observable/list/MappedList.js";
-import {ObservableValue} from "../../../../observable/ObservableValue.js";
+import {ObservableValue} from "../../../../observable/ObservableValue";
 import {PowerLevels} from "../../../../matrix/room/PowerLevels.js";
 
 export function tests() {
diff --git a/src/matrix/Session.js b/src/matrix/Session.js
index 63aece42..794cd622 100644
--- a/src/matrix/Session.js
+++ b/src/matrix/Session.js
@@ -40,7 +40,7 @@ import {
     writeKey as ssssWriteKey,
 } from "./ssss/index.js";
 import {SecretStorage} from "./ssss/SecretStorage.js";
-import {ObservableValue, RetainedObservableValue} from "../observable/ObservableValue.js";
+import {ObservableValue, RetainedObservableValue} from "../observable/ObservableValue";
 
 const PICKLE_KEY = "DEFAULT_KEY";
 const PUSHER_KEY = "pusher";
diff --git a/src/matrix/SessionContainer.js b/src/matrix/SessionContainer.js
index b58589d0..b645a9ec 100644
--- a/src/matrix/SessionContainer.js
+++ b/src/matrix/SessionContainer.js
@@ -18,7 +18,7 @@ limitations under the License.
 import {createEnum} from "../utils/enum.js";
 import {lookupHomeserver} from "./well-known.js";
 import {AbortableOperation} from "../utils/AbortableOperation";
-import {ObservableValue} from "../observable/ObservableValue.js";
+import {ObservableValue} from "../observable/ObservableValue";
 import {HomeServerApi} from "./net/HomeServerApi.js";
 import {Reconnector, ConnectionStatus} from "./net/Reconnector.js";
 import {ExponentialRetryDelay} from "./net/ExponentialRetryDelay.js";
diff --git a/src/matrix/Sync.js b/src/matrix/Sync.js
index bcd29ab4..e010f90d 100644
--- a/src/matrix/Sync.js
+++ b/src/matrix/Sync.js
@@ -15,7 +15,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {ObservableValue} from "../observable/ObservableValue.js";
+import {ObservableValue} from "../observable/ObservableValue";
 import {createEnum} from "../utils/enum.js";
 
 const INCREMENTAL_TIMEOUT = 30000;
diff --git a/src/matrix/net/Reconnector.js b/src/matrix/net/Reconnector.js
index d3cf790f..6fd2ca94 100644
--- a/src/matrix/net/Reconnector.js
+++ b/src/matrix/net/Reconnector.js
@@ -15,7 +15,7 @@ limitations under the License.
 */
 
 import {createEnum} from "../../utils/enum.js";
-import {ObservableValue} from "../../observable/ObservableValue.js";
+import {ObservableValue} from "../../observable/ObservableValue";
 
 export const ConnectionStatus = createEnum(
     "Waiting",
diff --git a/src/matrix/room/BaseRoom.js b/src/matrix/room/BaseRoom.js
index aac962ac..43b2cf51 100644
--- a/src/matrix/room/BaseRoom.js
+++ b/src/matrix/room/BaseRoom.js
@@ -29,7 +29,7 @@ import {ObservedEventMap} from "./ObservedEventMap.js";
 import {DecryptionSource} from "../e2ee/common.js";
 import {ensureLogItem} from "../../logging/utils.js";
 import {PowerLevels} from "./PowerLevels.js";
-import {RetainedObservableValue} from "../../observable/ObservableValue.js";
+import {RetainedObservableValue} from "../../observable/ObservableValue";
 
 const EVENT_ENCRYPTED_TYPE = "m.room.encrypted";
 
diff --git a/src/matrix/room/ObservedEventMap.js b/src/matrix/room/ObservedEventMap.js
index 59f0e26a..6b20f85e 100644
--- a/src/matrix/room/ObservedEventMap.js
+++ b/src/matrix/room/ObservedEventMap.js
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {BaseObservableValue} from "../../observable/ObservableValue.js";
+import {BaseObservableValue} from "../../observable/ObservableValue";
 
 export class ObservedEventMap {
     constructor(notifyEmpty) {
diff --git a/src/mocks/Clock.js b/src/mocks/Clock.js
index 97b7462a..440c4cb4 100644
--- a/src/mocks/Clock.js
+++ b/src/mocks/Clock.js
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {ObservableValue} from "../observable/ObservableValue.js";
+import {ObservableValue} from "../observable/ObservableValue";
 
 class Timeout {
     constructor(elapsed, ms) {
diff --git a/src/observable/ObservableValue.js b/src/observable/ObservableValue.ts
similarity index 100%
rename from src/observable/ObservableValue.js
rename to src/observable/ObservableValue.ts
diff --git a/src/platform/web/dom/History.js b/src/platform/web/dom/History.js
index 68e4ef78..d51974bb 100644
--- a/src/platform/web/dom/History.js
+++ b/src/platform/web/dom/History.js
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {BaseObservableValue} from "../../../observable/ObservableValue.js";
+import {BaseObservableValue} from "../../../observable/ObservableValue";
 
 export class History extends BaseObservableValue {
     handleEvent(event) {
diff --git a/src/platform/web/dom/OnlineStatus.js b/src/platform/web/dom/OnlineStatus.js
index 588c0815..48e4e912 100644
--- a/src/platform/web/dom/OnlineStatus.js
+++ b/src/platform/web/dom/OnlineStatus.js
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {BaseObservableValue} from "../../../observable/ObservableValue.js";
+import {BaseObservableValue} from "../../../observable/ObservableValue";
 
 export class OnlineStatus extends BaseObservableValue {
     constructor() {