diff --git a/src/domain/session/room/timeline/ReactionsViewModel.js b/src/domain/session/room/timeline/ReactionsViewModel.js
index f0dcf79f..ca5d43f0 100644
--- a/src/domain/session/room/timeline/ReactionsViewModel.js
+++ b/src/domain/session/room/timeline/ReactionsViewModel.js
@@ -181,7 +181,7 @@ import {FragmentIdComparer} from "../../../../matrix/room/timeline/FragmentIdCom
 import {createAnnotation} from "../../../../matrix/room/timeline/relations.js";
 // mocks
 import {Clock as MockClock} from "../../../../mocks/Clock.js";
-import {createMockStorage} from "../../../../mocks/Storage.js";
+import {createMockStorage} from "../../../../mocks/Storage";
 import {ListObserver} from "../../../../mocks/ListObserver.js";
 import {createEvent, withTextBody, withContent} from "../../../../mocks/event.js";
 import {NullLogItem, NullLogger} from "../../../../logging/NullLogger.js";
diff --git a/src/matrix/room/sending/SendQueue.js b/src/matrix/room/sending/SendQueue.js
index fec40397..28408e34 100644
--- a/src/matrix/room/sending/SendQueue.js
+++ b/src/matrix/room/sending/SendQueue.js
@@ -351,7 +351,7 @@ export class SendQueue {
 }
 
 import {HomeServer as MockHomeServer} from "../../../mocks/HomeServer.js";
-import {createMockStorage} from "../../../mocks/Storage.js";
+import {createMockStorage} from "../../../mocks/Storage";
 import {ListObserver} from "../../../mocks/ListObserver.js";
 import {NullLogger, NullLogItem} from "../../../logging/NullLogger.js";
 import {createEvent, withTextBody, withTxnId} from "../../../mocks/event.js";
diff --git a/src/matrix/room/timeline/Timeline.js b/src/matrix/room/timeline/Timeline.js
index 9169b029..4e6fe40c 100644
--- a/src/matrix/room/timeline/Timeline.js
+++ b/src/matrix/room/timeline/Timeline.js
@@ -343,7 +343,7 @@ export class Timeline {
 import {FragmentIdComparer} from "./FragmentIdComparer.js";
 import {poll} from "../../../mocks/poll.js";
 import {Clock as MockClock} from "../../../mocks/Clock.js";
-import {createMockStorage} from "../../../mocks/Storage.js";
+import {createMockStorage} from "../../../mocks/Storage";
 import {ListObserver} from "../../../mocks/ListObserver.js";
 import {createEvent, withTextBody, withContent, withSender} from "../../../mocks/event.js";
 import {NullLogItem} from "../../../logging/NullLogger.js";
diff --git a/src/matrix/room/timeline/persistence/GapWriter.js b/src/matrix/room/timeline/persistence/GapWriter.js
index 8d81288c..7794b797 100644
--- a/src/matrix/room/timeline/persistence/GapWriter.js
+++ b/src/matrix/room/timeline/persistence/GapWriter.js
@@ -203,7 +203,7 @@ export class GapWriter {
 
 import {FragmentIdComparer} from "../FragmentIdComparer.js";
 import {RelationWriter} from "./RelationWriter.js";
-import {createMockStorage} from "../../../../mocks/Storage.js";
+import {createMockStorage} from "../../../../mocks/Storage";
 import {FragmentBoundaryEntry} from "../entries/FragmentBoundaryEntry.js";
 import {NullLogItem} from "../../../../logging/NullLogger.js";
 import {TimelineMock, eventIds, eventId} from "../../../../mocks/TimelineMock.ts";
diff --git a/src/matrix/room/timeline/persistence/RelationWriter.js b/src/matrix/room/timeline/persistence/RelationWriter.js
index 0466b3da..c0d3d369 100644
--- a/src/matrix/room/timeline/persistence/RelationWriter.js
+++ b/src/matrix/room/timeline/persistence/RelationWriter.js
@@ -253,7 +253,7 @@ const _REDACT_KEEP_CONTENT_MAP = {
 };
 // end of matrix-js-sdk code
 
-import {createMockStorage} from "../../../../mocks/Storage.js";
+import {createMockStorage} from "../../../../mocks/Storage";
 import {createEvent, withTextBody, withRedacts, withContent} from "../../../../mocks/event.js";
 import {createAnnotation} from "../relations.js";
 import {FragmentIdComparer} from "../FragmentIdComparer.js";
diff --git a/src/matrix/room/timeline/persistence/SyncWriter.js b/src/matrix/room/timeline/persistence/SyncWriter.js
index af6f55bc..749c3392 100644
--- a/src/matrix/room/timeline/persistence/SyncWriter.js
+++ b/src/matrix/room/timeline/persistence/SyncWriter.js
@@ -256,7 +256,7 @@ export class SyncWriter {
     }
 }
 
-import {createMockStorage} from "../../../../mocks/Storage.js";
+import {createMockStorage} from "../../../../mocks/Storage";
 import {createEvent, withTextBody} from "../../../../mocks/event.js";
 import {Instance as nullLogger} from "../../../../logging/NullLogger.js";
 export function tests() {
diff --git a/src/matrix/storage/idb/stores/TimelineEventStore.ts b/src/matrix/storage/idb/stores/TimelineEventStore.ts
index 1d261f4a..75428d87 100644
--- a/src/matrix/storage/idb/stores/TimelineEventStore.ts
+++ b/src/matrix/storage/idb/stores/TimelineEventStore.ts
@@ -317,7 +317,7 @@ export class TimelineEventStore {
     }
 }
 
-import {createMockStorage} from "../../../../mocks/Storage.js";
+import {createMockStorage} from "../../../../mocks/Storage";
 import {createEvent, withTextBody} from "../../../../mocks/event.js";
 import {createEventEntry} from "../../../room/timeline/persistence/common.js";
 
diff --git a/src/matrix/storage/idb/utils.ts b/src/matrix/storage/idb/utils.ts
index a9432139..ca6e06de 100644
--- a/src/matrix/storage/idb/utils.ts
+++ b/src/matrix/storage/idb/utils.ts
@@ -68,7 +68,7 @@ export function decodeUint32(str: string): number {
     return parseInt(str, 16);
 }
 
-type CreateObjectStore = (db : IDBDatabase, txn: IDBTransaction | null, oldVersion: number, version: number) => any
+export type CreateObjectStore = (db : IDBDatabase, txn: IDBTransaction | null, oldVersion: number, version: number) => any
 
 export function openDatabase(name: string, createObjectStore: CreateObjectStore, version: number, idbFactory: IDBFactory = window.indexedDB): Promise<IDBDatabase> {
     const req = idbFactory.open(name, version);
diff --git a/src/mocks/Storage.js b/src/mocks/Storage.ts
similarity index 52%
rename from src/mocks/Storage.js
rename to src/mocks/Storage.ts
index 876cc009..2adf8001 100644
--- a/src/mocks/Storage.js
+++ b/src/mocks/Storage.ts
@@ -16,8 +16,26 @@ limitations under the License.
 
 import {FDBFactory, FDBKeyRange} from "../../lib/fake-indexeddb/index.js";
 import {StorageFactory} from "../matrix/storage/idb/StorageFactory";
+import {Storage} from "../matrix/storage/idb/Storage";
 import {Instance as nullLogger} from "../logging/NullLogger.js";
+import {openDatabase, CreateObjectStore} from "../matrix/storage/idb/utils";
 
-export function createMockStorage() {
-    return new StorageFactory(null, new FDBFactory(), FDBKeyRange).create(1, nullLogger.item);
+export function createMockStorage(): Promise<Storage> {
+    return new StorageFactory(null as any, new FDBFactory(), FDBKeyRange).create("1", nullLogger.item);
+}
+
+export function createMockDatabase(name: string, createObjectStore: CreateObjectStore, impl: MockIDBImpl): Promise<IDBDatabase> {
+    return openDatabase(name, createObjectStore, 1, impl.idbFactory);
+}
+
+export class MockIDBImpl {
+    idbFactory: FDBFactory;
+
+    constructor() {
+        this.idbFactory = new FDBFactory();
+    }
+
+    get IDBKeyRange(): typeof IDBKeyRange {
+        return FDBKeyRange;
+    }
 }