diff --git a/src/button/ReactionToggleButton.test.tsx b/src/button/ReactionToggleButton.test.tsx
index 1ac43ebc..c7ac5aa0 100644
--- a/src/button/ReactionToggleButton.test.tsx
+++ b/src/button/ReactionToggleButton.test.tsx
@@ -6,7 +6,7 @@ Please see LICENSE in the repository root for full details.
 */
 
 import { act, render } from "@testing-library/react";
-import { expect, test } from "vitest";
+import { expect, test, vi } from "vitest";
 import { TooltipProvider } from "@vector-im/compound-web";
 import { userEvent } from "@testing-library/user-event";
 import { type ReactNode } from "react";
@@ -19,6 +19,8 @@ import { alice, local, localRtcMember } from "../utils/test-fixtures";
 import { type MockRTCSession } from "../utils/test";
 import { ReactionsSenderProvider } from "../reactions/useReactionsSender";
 
+vi.mock("livekit-client/e2ee-worker?worker");
+
 const localIdent = `${localRtcMember.userId}:${localRtcMember.deviceId}`;
 
 function TestComponent({
diff --git a/src/room/CallEventAudioRenderer.test.tsx b/src/room/CallEventAudioRenderer.test.tsx
index bc1a1b39..e49c7011 100644
--- a/src/room/CallEventAudioRenderer.test.tsx
+++ b/src/room/CallEventAudioRenderer.test.tsx
@@ -7,7 +7,6 @@ Please see LICENSE in the repository root for full details.
 
 import { render } from "@testing-library/react";
 import {
-  afterAll,
   beforeEach,
   expect,
   type MockedFunction,
@@ -16,9 +15,17 @@ import {
   afterEach,
 } from "vitest";
 import { act } from "react";
-import { type CallMembership } from "matrix-js-sdk/lib/matrixrtc";
+import { type RoomMember } from "matrix-js-sdk";
+import {
+  type LivekitTransport,
+  type CallMembership,
+} from "matrix-js-sdk/lib/matrixrtc";
 
-import { mockRtcMembership } from "../utils/test";
+import {
+  exampleTransport,
+  mockMatrixRoomMember,
+  mockRtcMembership,
+} from "../utils/test";
 import { CallEventAudioRenderer } from "./CallEventAudioRenderer";
 import { useAudioContext } from "../useAudioContext";
 import { prefetchSounds } from "../soundUtils";
@@ -26,21 +33,23 @@ import { getBasicCallViewModelEnvironment } from "../utils/test-viewmodel";
 import {
   alice,
   aliceRtcMember,
+  bob,
   bobRtcMember,
   local,
   localRtcMember,
 } from "../utils/test-fixtures";
 import { MAX_PARTICIPANT_COUNT_FOR_SOUND } from "../state/CallViewModel";
 
+vitest.mock("livekit-client/e2ee-worker?worker");
 vitest.mock("../useAudioContext");
 vitest.mock("../soundUtils");
+vitest.mock("../rtcSessionHelpers", async (importOriginal) => ({
+  ...(await importOriginal()),
+  makeTransport: (): [LivekitTransport] => [exampleTransport],
+}));
 
 afterEach(() => {
-  vitest.resetAllMocks();
-});
-
-afterAll(() => {
-  vitest.restoreAllMocks();
+  vitest.clearAllMocks();
 });
 
 let playSound: MockedFunction<
@@ -70,6 +79,7 @@ test("plays one sound when entering a call", () => {
   const { vm, rtcMemberships$ } = getBasicCallViewModelEnvironment([
     local,
     alice,
+    bob,
   ]);
   render(<CallEventAudioRenderer vm={vm} />);
 
@@ -84,6 +94,7 @@ test("plays a sound when a user joins", () => {
   const { vm, rtcMemberships$ } = getBasicCallViewModelEnvironment([
     local,
     alice,
+    bob,
   ]);
   render(<CallEventAudioRenderer vm={vm} />);
 
@@ -122,15 +133,16 @@ test("does not play a sound before the call is successful", () => {
 });
 
 test("plays no sound when the participant list is more than the maximum size", () => {
+  const mockMembers: RoomMember[] = [local];
   const mockRtcMemberships: CallMembership[] = [localRtcMember];
   for (let i = 0; i < MAX_PARTICIPANT_COUNT_FOR_SOUND; i++) {
-    mockRtcMemberships.push(
-      mockRtcMembership(`@user${i}:example.org`, `DEVICE${i}`),
-    );
+    const membership = mockRtcMembership(`@user${i}:example.org`, `DEVICE${i}`);
+    mockMembers.push(mockMatrixRoomMember(membership));
+    mockRtcMemberships.push(membership);
   }
 
   const { vm, rtcMemberships$ } = getBasicCallViewModelEnvironment(
-    [local, alice],
+    mockMembers,
     mockRtcMemberships,
   );
 
@@ -150,6 +162,7 @@ test("plays one sound when a hand is raised", () => {
   const { vm, handRaisedSubject$ } = getBasicCallViewModelEnvironment([
     local,
     alice,
+    bob,
   ]);
   render(<CallEventAudioRenderer vm={vm} />);
 
diff --git a/src/room/InCallView.test.tsx b/src/room/InCallView.test.tsx
index 52a40702..d388ebc3 100644
--- a/src/room/InCallView.test.tsx
+++ b/src/room/InCallView.test.tsx
@@ -58,6 +58,7 @@ vi.mock("../useAudioContext");
 vi.mock("../tile/GridTile");
 vi.mock("../tile/SpotlightTile");
 vi.mock("@livekit/components-react");
+vi.mock("livekit-client/e2ee-worker?worker");
 vi.mock("../e2ee/sharedKeyManagement");
 vi.mock("../livekit/MatrixAudioRenderer");
 vi.mock("react-use-measure", () => ({
diff --git a/src/room/ReactionAudioRenderer.test.tsx b/src/room/ReactionAudioRenderer.test.tsx
index f301832e..83188be7 100644
--- a/src/room/ReactionAudioRenderer.test.tsx
+++ b/src/room/ReactionAudioRenderer.test.tsx
@@ -45,6 +45,7 @@ function TestComponent({ vm }: { vm: CallViewModel }): ReactNode {
   );
 }
 
+vitest.mock("livekit-client/e2ee-worker?worker");
 vitest.mock("../useAudioContext");
 vitest.mock("../soundUtils");
 
diff --git a/src/room/ReactionsOverlay.test.tsx b/src/room/ReactionsOverlay.test.tsx
index 6be69399..3ca82b1e 100644
--- a/src/room/ReactionsOverlay.test.tsx
+++ b/src/room/ReactionsOverlay.test.tsx
@@ -6,7 +6,7 @@ Please see LICENSE in the repository root for full details.
 */
 
 import { render } from "@testing-library/react";
-import { expect, test, afterEach } from "vitest";
+import { expect, test, afterEach, vi } from "vitest";
 import { act } from "react";
 
 import { showReactions } from "../settings/settings";
@@ -20,6 +20,8 @@ import {
 } from "../utils/test-fixtures";
 import { getBasicCallViewModelEnvironment } from "../utils/test-viewmodel";
 
+vi.mock("livekit-client/e2ee-worker?worker");
+
 afterEach(() => {
   showReactions.setValue(showReactions.defaultValue);
 });
diff --git a/src/room/__snapshots__/InCallView.test.tsx.snap b/src/room/__snapshots__/InCallView.test.tsx.snap
index 15709eef..661d13ad 100644
--- a/src/room/__snapshots__/InCallView.test.tsx.snap
+++ b/src/room/__snapshots__/InCallView.test.tsx.snap
@@ -83,20 +83,32 @@ exports[`InCallView > rendering > renders 1`] = `
         class="nav rightNav"
       />
     </header>
+    <div>
+      mocked: MatrixAudioRenderer
+    </div>
     <div
       class="scrollingGrid grid"
     >
       <div
-        class="scrolling"
-        style="--gap: 20px; --width: NaNpx; --height: NaNpx;"
-      />
+        class="layer"
+      >
+        <div
+          class="container slot"
+          data-id="1"
+        >
+          <div
+            class="slot local slot"
+            data-block-alignment="start"
+            data-id="0"
+            data-inline-alignment="end"
+          />
+        </div>
+      </div>
     </div>
     <div
       class="fixedGrid grid"
     >
-      <div
-        class="fixed"
-      />
+      <div />
     </div>
     <div
       class="bg animate"
diff --git a/src/utils/test-viewmodel.ts b/src/utils/test-viewmodel.ts
index fa6bb691..5cd64eb3 100644
--- a/src/utils/test-viewmodel.ts
+++ b/src/utils/test-viewmodel.ts
@@ -16,6 +16,7 @@ import {
   type Room,
   SyncState,
 } from "matrix-js-sdk";
+import { ConnectionState, type Room as LivekitRoom } from "livekit-client";
 
 import { E2eeType } from "../e2ee/e2eeType";
 import {
@@ -23,6 +24,8 @@ import {
   type CallViewModelOptions,
 } from "../state/CallViewModel";
 import {
+  mockLivekitRoom,
+  mockLocalParticipant,
   mockMatrixRoom,
   mockMediaDevices,
   mockMuteStates,
@@ -31,6 +34,7 @@ import {
 } from "./test";
 import { aliceRtcMember, localRtcMember } from "./test-fixtures";
 import { type RaisedHandInfo, type ReactionInfo } from "../reactions";
+import { constant } from "../state/Behavior";
 
 export function getBasicRTCSession(
   members: RoomMember[],
@@ -142,6 +146,14 @@ export function getBasicCallViewModelEnvironment(
     mockMuteStates(),
     {
       encryptionSystem: { kind: E2eeType.PER_PARTICIPANT },
+      livekitRoomFactory: (): LivekitRoom =>
+        mockLivekitRoom({
+          localParticipant: mockLocalParticipant({ identity: "" }),
+          remoteParticipants: new Map(),
+          disconnect: async () => Promise.resolve(),
+          setE2EEEnabled: async () => Promise.resolve(),
+        }),
+      connectionState$: constant(ConnectionState.Connected),
       ...callViewModelOptions,
     },
     handRaisedSubject$,