diff --git a/src/AppBar.tsx b/src/AppBar.tsx
index ba41629f..6135a3a8 100644
--- a/src/AppBar.tsx
+++ b/src/AppBar.tsx
@@ -71,8 +71,8 @@ export const AppBar: FC<Props> = ({ children }) => {
         >
           <LeftNav>
             <Tooltip label={t("common.back")}>
-              <IconButton onClick={onBackClick}>
-                <CollapseIcon />
+              <IconButton size="24px" onClick={onBackClick}>
+                <CollapseIcon aria-hidden />
               </IconButton>
             </Tooltip>
           </LeftNav>
diff --git a/src/button/Button.tsx b/src/button/Button.tsx
index 1ad5b124..9dec7d9c 100644
--- a/src/button/Button.tsx
+++ b/src/button/Button.tsx
@@ -193,7 +193,7 @@ export const SettingsIconButton: FC<SettingsIconButtonProps> = ({
         className={classNamesForScrrenWidth(className, showForScreenWidth)}
         {...props}
       >
-        <Icon />
+        <Icon aria-hidden/>
       </IconButton>
     </Tooltip>
   );
diff --git a/src/room/CallEventAudioRenderer.test.tsx b/src/room/CallEventAudioRenderer.test.tsx
index 5d3eff5e..9ab64dfd 100644
--- a/src/room/CallEventAudioRenderer.test.tsx
+++ b/src/room/CallEventAudioRenderer.test.tsx
@@ -123,6 +123,7 @@ test("does not play a sound before the call is successful", () => {
   const { vm, rtcMemberships$ } = getBasicCallViewModelEnvironment(
     [local, alice],
     [localRtcMember],
+    undefined,
     { waitForCallPickup: true },
   );
   render(<CallEventAudioRenderer vm={vm} />);
diff --git a/src/room/InCallView.test.tsx b/src/room/InCallView.test.tsx
index 50f586ab..692b920c 100644
--- a/src/room/InCallView.test.tsx
+++ b/src/room/InCallView.test.tsx
@@ -109,6 +109,7 @@ interface CreateInCallViewArgs {
 function createInCallView(args: CreateInCallViewArgs = {}): RenderResult & {
   rtcSession: MockRTCSession;
 } {
+  const mediaDevices = args.mediaDevices ?? mockMediaDevices({});
   const muteState = mockMuteStates();
   const livekitRoom = mockLivekitRoom(
     {
@@ -121,10 +122,8 @@ function createInCallView(args: CreateInCallViewArgs = {}): RenderResult & {
   const { vm, rtcSession } = getBasicCallViewModelEnvironment(
     [local, alice],
     undefined,
-    {
-      toggleScreensharing: () => {},
-      ...args.callViewModelOptions,
-    },
+    mediaDevices,
+    {},
   );
 
   rtcSession.joined = true;
@@ -166,7 +165,7 @@ function createInCallView(args: CreateInCallViewArgs = {}): RenderResult & {
 
   const renderResult = render(
     <Router>
-      <MediaDevicesContext value={args.mediaDevices ?? mockMediaDevices({})}>
+      <MediaDevicesContext value={mediaDevices}>
         <ReactionsSenderProvider
           vm={vm}
           rtcSession={rtcSession.asMockedSession()}
@@ -263,9 +262,7 @@ describe("InCallView", () => {
         },
       });
 
-      const { getByRole } = createInCallView({
-        callViewModelOptions: { mediaDeviceOverride: mediaDevices },
-      });
+      const { getByRole } = createInCallView({ mediaDevices });
       // The button should be visible. When current output is "speaker",
       // the switcher targets "earpiece", so the tooltip label is "Handset".
       const audioOutputBtn = getByRole("switch", { name: "Handset" });
diff --git a/src/state/CallViewModel/CallViewModel.ts b/src/state/CallViewModel/CallViewModel.ts
index 410ec922..7bfe4630 100644
--- a/src/state/CallViewModel/CallViewModel.ts
+++ b/src/state/CallViewModel/CallViewModel.ts
@@ -175,7 +175,6 @@ export interface CallViewModelOptions {
   matrixRTCMode$?: Behavior<MatrixRTCMode>;
   /** Optional behavior overriding for the screensharing, for testing */
   toggleScreensharing?: () => void;
-  mediaDeviceOverride?: MediaDevices;
 }
 
 // Do not play any sounds if the participant count has exceeded this
diff --git a/src/utils/test-viewmodel.ts b/src/utils/test-viewmodel.ts
index 6d77a802..b5438371 100644
--- a/src/utils/test-viewmodel.ts
+++ b/src/utils/test-viewmodel.ts
@@ -34,6 +34,7 @@ import {
   MockRTCSession,
   testScope,
 } from "./test";
+import { type MediaDevices } from "../state/MediaDevices";
 import { aliceRtcMember, localRtcMember } from "./test-fixtures";
 import { type RaisedHandInfo, type ReactionInfo } from "../reactions";
 import { constant } from "../state/Behavior";
@@ -131,6 +132,7 @@ export function getBasicRTCSession(
 export function getBasicCallViewModelEnvironment(
   members: RoomMember[],
   initialRtcMemberships: CallMembership[] = [localRtcMember, aliceRtcMember],
+  mediaDevicesOverride?: MediaDevices,
   callViewModelOptions: Partial<CallViewModelOptions> = {},
 ): {
   vm: CallViewModel;
@@ -146,13 +148,11 @@ export function getBasicCallViewModelEnvironment(
   const handRaisedSubject$ = new BehaviorSubject({});
   const reactionsSubject$ = new BehaviorSubject({});
 
-  // const remoteParticipants$ = of([aliceParticipant]);
-
   const vm = createCallViewModel$(
     testScope(),
     rtcSession.asMockedSession(),
     matrixRoom,
-    callViewModelOptions.mediaDeviceOverride ?? mockMediaDevices({}),
+    mediaDevicesOverride ?? mockMediaDevices({}),
     mockMuteStates(),
     {
       encryptionSystem: { kind: E2eeType.PER_PARTICIPANT },