diff --git a/src/room/InCallView.tsx b/src/room/InCallView.tsx
index add8154a..41582039 100644
--- a/src/room/InCallView.tsx
+++ b/src/room/InCallView.tsx
@@ -88,6 +88,7 @@ import { ReactionsOverlay } from "./ReactionsOverlay";
 import { CallEventAudioRenderer } from "./CallEventAudioRenderer";
 import {
   debugTileLayout as debugTileLayoutSetting,
+  matrixRTCMode as matrixRTCModeSetting,
   useSetting,
 } from "../settings/settings";
 import { ReactionsReader } from "../reactions/ReactionsReader";
@@ -144,6 +145,7 @@ export const ActiveCall: FC<ActiveCallProps> = (props) => {
         encryptionSystem: props.e2eeSystem,
         autoLeaveWhenOthersLeft,
         waitForCallPickup: waitForCallPickup && sendNotificationType === "ring",
+        matrixRTCMode$: matrixRTCModeSetting.value$,
       },
       reactionsReader.raisedHands$,
       reactionsReader.reactions$,
diff --git a/src/state/CallViewModel/CallViewModel.test.ts b/src/state/CallViewModel/CallViewModel.test.ts
index 2e5b5700..86cde12a 100644
--- a/src/state/CallViewModel/CallViewModel.test.ts
+++ b/src/state/CallViewModel/CallViewModel.test.ts
@@ -60,7 +60,8 @@ import {
 import { MediaDevices } from "../MediaDevices.ts";
 import { getValue } from "../../utils/observable.ts";
 import { type Behavior, constant } from "../Behavior.ts";
-import { withCallViewModel } from "./CallViewModelTestUtils.ts";
+import { withCallViewModel as withCallViewModelInMode } from "./CallViewModelTestUtils.ts";
+import { MatrixRTCMode } from "../../settings/settings.ts";
 
 vi.mock("rxjs", async (importOriginal) => ({
   ...(await importOriginal()),
@@ -229,7 +230,13 @@ function mockRingEvent(
 // need a value to fill in for them when emitting notifications
 const mockLegacyRingEvent = {} as { event_id: string } & ICallNotifyContent;
 
-describe("CallViewModel", () => {
+describe.each([
+  [MatrixRTCMode.Legacy],
+  [MatrixRTCMode.Compatibil],
+  [MatrixRTCMode.Matrix_2_0],
+])("CallViewModel (%s mode)", (mode) => {
+  const withCallViewModel = withCallViewModelInMode(mode);
+
   test("participants are retained during a focus switch", () => {
     withTestScheduler(({ behavior, expectObservable }) => {
       // Participants disappear on frame 2 and come back on frame 3
diff --git a/src/state/CallViewModel/CallViewModel.ts b/src/state/CallViewModel/CallViewModel.ts
index aac88a3b..8f8b20cf 100644
--- a/src/state/CallViewModel/CallViewModel.ts
+++ b/src/state/CallViewModel/CallViewModel.ts
@@ -53,11 +53,15 @@ import {
   ScreenShareViewModel,
   type UserMediaViewModel,
 } from "../MediaViewModel";
-import { accumulate, generateItems, pauseWhen } from "../../utils/observable";
+import {
+  accumulate,
+  filterBehavior,
+  generateItems,
+  pauseWhen,
+} from "../../utils/observable";
 import {
   duplicateTiles,
   MatrixRTCMode,
-  matrixRTCMode,
   playReactionsSound,
   showReactions,
 } from "../../settings/settings";
@@ -111,7 +115,8 @@ import { ECConnectionFactory } from "./remoteMembers/ConnectionFactory.ts";
 import { createConnectionManager$ } from "./remoteMembers/ConnectionManager.ts";
 import {
   createMatrixLivekitMembers$,
-  type MatrixLivekitMember,
+  type TaggedParticipant,
+  type LocalMatrixLivekitMember,
 } from "./remoteMembers/MatrixLivekitMembers.ts";
 import {
   type AutoLeaveReason,
@@ -150,6 +155,8 @@ export interface CallViewModelOptions {
   connectionState$?: Behavior<ConnectionState>;
   /** Optional behavior overriding the computed window size, mainly for testing purposes. */
   windowSize$?: Behavior<{ width: number; height: number }>;
+  /** The version & compatibility mode of MatrixRTC that we should use. */
+  matrixRTCMode$: Behavior<MatrixRTCMode>;
 }
 
 // Do not play any sounds if the participant count has exceeded this
@@ -406,7 +413,7 @@ export function createCallViewModel$(
     client,
     roomId: matrixRoom.roomId,
     useOldestMember$: scope.behavior(
-      matrixRTCMode.value$.pipe(map((v) => v === MatrixRTCMode.Legacy)),
+      options.matrixRTCMode$.pipe(map((v) => v === MatrixRTCMode.Legacy)),
     ),
   });
 
@@ -458,7 +465,7 @@ export function createCallViewModel$(
   });
 
   const connectOptions$ = scope.behavior(
-    matrixRTCMode.value$.pipe(
+    options.matrixRTCMode$.pipe(
       map((mode) => ({
         encryptMedia: livekitKeyProvider !== undefined,
         // TODO. This might need to get called again on each change of matrixRTCMode...
@@ -512,22 +519,21 @@ export function createCallViewModel$(
     ),
   );
 
-  const localMatrixLivekitMemberUninitialized = {
-    membership$: localRtcMembership$,
-    participant$: localMembership.participant$,
-    connection$: localMembership.connection$,
-    userId: userId,
-  };
-
-  const localMatrixLivekitMember$: Behavior<MatrixLivekitMember | null> =
+  const localMatrixLivekitMember$: Behavior<LocalMatrixLivekitMember | null> =
     scope.behavior(
       localRtcMembership$.pipe(
-        switchMap((membership) => {
-          if (!membership) return of(null);
-          return of(
-            // casting is save here since we know that localRtcMembership$ is !== null since we reached this case.
-            localMatrixLivekitMemberUninitialized as MatrixLivekitMember,
-          );
+        filterBehavior((membership) => membership !== null),
+        map((membership$) => {
+          if (membership$ === null) return null;
+          return {
+            membership$,
+            participant: {
+              type: "local" as const,
+              value$: localMembership.participant$,
+            },
+            connection$: localMembership.connection$,
+            userId,
+          };
         }),
       ),
     );
@@ -596,7 +602,7 @@ export function createCallViewModel$(
         const members = membersWithEpoch.value;
         const a$ = combineLatest(
           members.map((member) =>
-            combineLatest([member.connection$, member.participant$]).pipe(
+            combineLatest([member.connection$, member.participant.value$]).pipe(
               map(([connection, participant]) => {
                 // do not render audio for local participant
                 if (!connection || !participant || participant.isLocal)
@@ -674,7 +680,7 @@ export function createCallViewModel$(
           let localParticipantId: string | undefined = undefined;
           // add local member if available
           if (localMatrixLivekitMember) {
-            const { userId, participant$, connection$, membership$ } =
+            const { userId, participant, connection$, membership$ } =
               localMatrixLivekitMember;
             localParticipantId = `${userId}:${membership$.value.deviceId}`; // should be membership$.value.membershipID which is not optional
             // const participantId = membership$.value.membershipID;
@@ -685,7 +691,7 @@ export function createCallViewModel$(
                     dup,
                     localParticipantId,
                     userId,
-                    participant$,
+                    participant satisfies TaggedParticipant as TaggedParticipant, // Widen the type safely
                     connection$,
                   ],
                   data: undefined,
@@ -696,7 +702,7 @@ export function createCallViewModel$(
           // add remote members that are available
           for (const {
             userId,
-            participant$,
+            participant,
             connection$,
             membership$,
           } of matrixLivekitMembers) {
@@ -705,7 +711,7 @@ export function createCallViewModel$(
             // const participantId = membership$.value?.identity;
             for (let dup = 0; dup < 1 + duplicateTiles; dup++) {
               yield {
-                keys: [dup, participantId, userId, participant$, connection$],
+                keys: [dup, participantId, userId, participant, connection$],
                 data: undefined,
               };
             }
@@ -717,7 +723,7 @@ export function createCallViewModel$(
           dup,
           participantId,
           userId,
-          participant$,
+          participant,
           connection$,
         ) => {
           const livekitRoom$ = scope.behavior(
@@ -736,7 +742,7 @@ export function createCallViewModel$(
             scope,
             `${participantId}:${dup}`,
             userId,
-            participant$,
+            participant,
             options.encryptionSystem,
             livekitRoom$,
             focusUrl$,
diff --git a/src/state/CallViewModel/CallViewModelTestUtils.ts b/src/state/CallViewModel/CallViewModelTestUtils.ts
index f80b4bcb..b6f53275 100644
--- a/src/state/CallViewModel/CallViewModelTestUtils.ts
+++ b/src/state/CallViewModel/CallViewModelTestUtils.ts
@@ -53,6 +53,7 @@ import {
 import { type Behavior, constant } from "../Behavior";
 import { type ProcessorState } from "../../livekit/TrackProcessorContext";
 import { type MediaDevices } from "../MediaDevices";
+import { type MatrixRTCMode } from "../../settings/settings";
 
 mockConfig({
   livekit: { livekit_service_url: "http://my-default-service-url.com" },
@@ -80,117 +81,125 @@ export interface CallViewModelInputs {
 
 const localParticipant = mockLocalParticipant({ identity: "" });
 
-export function withCallViewModel(
-  {
-    remoteParticipants$ = constant([]),
-    rtcMembers$ = constant([localRtcMember]),
-    livekitConnectionState$: connectionState$ = constant(
-      ConnectionState.Connected,
-    ),
-    speaking = new Map(),
-    mediaDevices = mockMediaDevices({}),
-    initialSyncState = SyncState.Syncing,
-    windowSize$ = constant({ width: 1000, height: 800 }),
-  }: Partial<CallViewModelInputs> = {},
-  continuation: (
-    vm: CallViewModel,
-    rtcSession: MockRTCSession,
-    subjects: { raisedHands$: BehaviorSubject<Record<string, RaisedHandInfo>> },
-    setSyncState: (value: SyncState) => void,
-  ) => void,
-  options: CallViewModelOptions = {
-    encryptionSystem: { kind: E2eeType.PER_PARTICIPANT },
-    autoLeaveWhenOthersLeft: false,
-  },
-): void {
-  let syncState = initialSyncState;
-  const setSyncState = (value: SyncState): void => {
-    const prev = syncState;
-    syncState = value;
-    room.client.emit(ClientEvent.Sync, value, prev);
-  };
-  const room = mockMatrixRoom({
-    client: new (class extends EventEmitter {
-      public getUserId(): string | undefined {
-        return localRtcMember.userId;
-      }
+export function withCallViewModel(mode: MatrixRTCMode) {
+  return (
+    {
+      remoteParticipants$ = constant([]),
+      rtcMembers$ = constant([localRtcMember]),
+      livekitConnectionState$: connectionState$ = constant(
+        ConnectionState.Connected,
+      ),
+      speaking = new Map(),
+      mediaDevices = mockMediaDevices({}),
+      initialSyncState = SyncState.Syncing,
+      windowSize$ = constant({ width: 1000, height: 800 }),
+    }: Partial<CallViewModelInputs> = {},
+    continuation: (
+      vm: CallViewModel,
+      rtcSession: MockRTCSession,
+      subjects: {
+        raisedHands$: BehaviorSubject<Record<string, RaisedHandInfo>>;
+      },
+      setSyncState: (value: SyncState) => void,
+    ) => void,
+    options: Partial<CallViewModelOptions> = {},
+  ): void => {
+    let syncState = initialSyncState;
+    const setSyncState = (value: SyncState): void => {
+      const prev = syncState;
+      syncState = value;
+      room.client.emit(ClientEvent.Sync, value, prev);
+    };
+    const room = mockMatrixRoom({
+      client: new (class extends EventEmitter {
+        public getUserId(): string | undefined {
+          return localRtcMember.userId;
+        }
 
-      public getDeviceId(): string {
-        return localRtcMember.deviceId;
-      }
+        public getDeviceId(): string {
+          return localRtcMember.deviceId;
+        }
 
-      public getDomain(): string {
-        return "example.com";
-      }
+        public getDomain(): string {
+          return "example.com";
+        }
 
-      public getSyncState(): SyncState {
-        return syncState;
-      }
-    })() as Partial<MatrixClient> as MatrixClient,
-    getMembers: () => Array.from(roomMembers.values()),
-    getMembersWithMembership: () => Array.from(roomMembers.values()),
-  });
-  const rtcSession = new MockRTCSession(room, []).withMemberships(rtcMembers$);
-  const participantsSpy = vi
-    .spyOn(ComponentsCore, "connectedParticipantsObserver")
-    .mockReturnValue(remoteParticipants$);
-  const mediaSpy = vi
-    .spyOn(ComponentsCore, "observeParticipantMedia")
-    .mockImplementation((p) =>
-      of({ participant: p } as Partial<
-        ComponentsCore.ParticipantMedia<LocalParticipant>
-      > as ComponentsCore.ParticipantMedia<LocalParticipant>),
+        public getSyncState(): SyncState {
+          return syncState;
+        }
+      })() as Partial<MatrixClient> as MatrixClient,
+      getMembers: () => Array.from(roomMembers.values()),
+      getMembersWithMembership: () => Array.from(roomMembers.values()),
+    });
+    const rtcSession = new MockRTCSession(room, []).withMemberships(
+      rtcMembers$,
     );
-  const eventsSpy = vi
-    .spyOn(ComponentsCore, "observeParticipantEvents")
-    .mockImplementation((p, ...eventTypes) => {
-      if (eventTypes.includes(ParticipantEvent.IsSpeakingChanged)) {
-        return (speaking.get(p) ?? of(false)).pipe(
-          map((s): Participant => ({ ...p, isSpeaking: s }) as Participant),
-        );
-      } else {
-        return of(p);
-      }
+    const participantsSpy = vi
+      .spyOn(ComponentsCore, "connectedParticipantsObserver")
+      .mockReturnValue(remoteParticipants$);
+    const mediaSpy = vi
+      .spyOn(ComponentsCore, "observeParticipantMedia")
+      .mockImplementation((p) =>
+        of({ participant: p } as Partial<
+          ComponentsCore.ParticipantMedia<LocalParticipant>
+        > as ComponentsCore.ParticipantMedia<LocalParticipant>),
+      );
+    const eventsSpy = vi
+      .spyOn(ComponentsCore, "observeParticipantEvents")
+      .mockImplementation((p, ...eventTypes) => {
+        if (eventTypes.includes(ParticipantEvent.IsSpeakingChanged)) {
+          return (speaking.get(p) ?? of(false)).pipe(
+            map((s): Participant => ({ ...p, isSpeaking: s }) as Participant),
+          );
+        } else {
+          return of(p);
+        }
+      });
+
+    const roomEventSelectorSpy = vi
+      .spyOn(ComponentsCore, "roomEventSelector")
+      .mockImplementation((_room, _eventType) => of());
+    const muteStates = mockMuteStates();
+    const raisedHands$ = new BehaviorSubject<Record<string, RaisedHandInfo>>(
+      {},
+    );
+    const reactions$ = new BehaviorSubject<Record<string, ReactionInfo>>({});
+
+    const vm = createCallViewModel$(
+      testScope(),
+      rtcSession.asMockedSession(),
+      room,
+      mediaDevices,
+      muteStates,
+      {
+        encryptionSystem: { kind: E2eeType.PER_PARTICIPANT },
+        autoLeaveWhenOthersLeft: false,
+        livekitRoomFactory: (): LivekitRoom =>
+          mockLivekitRoom({
+            localParticipant,
+            disconnect: async () => Promise.resolve(),
+            setE2EEEnabled: async () => Promise.resolve(),
+          }),
+        connectionState$,
+        windowSize$,
+        matrixRTCMode$: constant(mode),
+        ...options,
+      },
+      raisedHands$,
+      reactions$,
+      new BehaviorSubject<ProcessorState>({
+        processor: undefined,
+        supported: undefined,
+      }),
+    );
+
+    onTestFinished(() => {
+      participantsSpy.mockRestore();
+      mediaSpy.mockRestore();
+      eventsSpy.mockRestore();
+      roomEventSelectorSpy.mockRestore();
     });
 
-  const roomEventSelectorSpy = vi
-    .spyOn(ComponentsCore, "roomEventSelector")
-    .mockImplementation((_room, _eventType) => of());
-  const muteStates = mockMuteStates();
-  const raisedHands$ = new BehaviorSubject<Record<string, RaisedHandInfo>>({});
-  const reactions$ = new BehaviorSubject<Record<string, ReactionInfo>>({});
-
-  const vm = createCallViewModel$(
-    testScope(),
-    rtcSession.asMockedSession(),
-    room,
-    mediaDevices,
-    muteStates,
-    {
-      ...options,
-      livekitRoomFactory: (): LivekitRoom =>
-        mockLivekitRoom({
-          localParticipant,
-          disconnect: async () => Promise.resolve(),
-          setE2EEEnabled: async () => Promise.resolve(),
-        }),
-      connectionState$,
-      windowSize$,
-    },
-    raisedHands$,
-    reactions$,
-    new BehaviorSubject<ProcessorState>({
-      processor: undefined,
-      supported: undefined,
-    }),
-  );
-
-  onTestFinished(() => {
-    participantsSpy.mockRestore();
-    mediaSpy.mockRestore();
-    eventsSpy.mockRestore();
-    roomEventSelectorSpy.mockRestore();
-  });
-
-  continuation(vm, rtcSession, { raisedHands$: raisedHands$ }, setSyncState);
+    continuation(vm, rtcSession, { raisedHands$: raisedHands$ }, setSyncState);
+  };
 }
diff --git a/src/state/CallViewModel/remoteMembers/Connection.test.ts b/src/state/CallViewModel/remoteMembers/Connection.test.ts
index 8f9471d0..4318708e 100644
--- a/src/state/CallViewModel/remoteMembers/Connection.test.ts
+++ b/src/state/CallViewModel/remoteMembers/Connection.test.ts
@@ -32,7 +32,6 @@ import {
   Connection,
   ConnectionState,
   type ConnectionOpts,
-  type PublishingParticipant,
 } from "./Connection.ts";
 import { ObservableScope } from "../../ObservableScope.ts";
 import { type OpenIDClientParts } from "../../../livekit/openIDSFU.ts";
@@ -395,7 +394,7 @@ describe("Publishing participants observations", () => {
 
     const bobIsAPublisher = Promise.withResolvers<void>();
     const danIsAPublisher = Promise.withResolvers<void>();
-    const observedPublishers: PublishingParticipant[][] = [];
+    const observedPublishers: RemoteParticipant[][] = [];
     const s = connection.remoteParticipantsWithTracks$.subscribe(
       (publishers) => {
         observedPublishers.push(publishers);
@@ -408,7 +407,7 @@ describe("Publishing participants observations", () => {
       },
     );
     onTestFinished(() => s.unsubscribe());
-    // The publishingParticipants$ observable is derived from the current members of the
+    // The remoteParticipants$ observable is derived from the current members of the
     // livekitRoom and the rtc membership in order to publish the members that are publishing
     // on this connection.
 
@@ -450,7 +449,7 @@ describe("Publishing participants observations", () => {
 
     const connection = setupRemoteConnection();
 
-    let observedPublishers: PublishingParticipant[][] = [];
+    let observedPublishers: RemoteParticipant[][] = [];
     const s = connection.remoteParticipantsWithTracks$.subscribe(
       (publishers) => {
         observedPublishers.push(publishers);
diff --git a/src/state/CallViewModel/remoteMembers/Connection.ts b/src/state/CallViewModel/remoteMembers/Connection.ts
index 8b4479e8..3d685c8a 100644
--- a/src/state/CallViewModel/remoteMembers/Connection.ts
+++ b/src/state/CallViewModel/remoteMembers/Connection.ts
@@ -13,7 +13,6 @@ import {
 import {
   ConnectionError,
   type Room as LivekitRoom,
-  type LocalParticipant,
   type RemoteParticipant,
   RoomEvent,
 } from "livekit-client";
@@ -35,8 +34,6 @@ import {
   UnknownCallError,
 } from "../../../utils/errors.ts";
 
-export type PublishingParticipant = LocalParticipant | RemoteParticipant;
-
 export interface ConnectionOpts {
   /** The media transport to connect to. */
   transport: LivekitTransport;
@@ -103,9 +100,7 @@ export class Connection {
    * This is derived from `participantsIncludingSubscribers$` and `remoteTransports$`.
    * It filters the participants to only those that are associated with a membership that claims to publish on this connection.
    */
-  public readonly remoteParticipantsWithTracks$: Behavior<
-    PublishingParticipant[]
-  >;
+  public readonly remoteParticipantsWithTracks$: Behavior<RemoteParticipant[]>;
 
   /**
    * Whether the connection has been stopped.
diff --git a/src/state/CallViewModel/remoteMembers/ConnectionManager.test.ts b/src/state/CallViewModel/remoteMembers/ConnectionManager.test.ts
index 484a44e7..da1da06f 100644
--- a/src/state/CallViewModel/remoteMembers/ConnectionManager.test.ts
+++ b/src/state/CallViewModel/remoteMembers/ConnectionManager.test.ts
@@ -8,7 +8,7 @@ Please see LICENSE in the repository root for full details.
 import { afterEach, beforeEach, describe, expect, test, vi } from "vitest";
 import { BehaviorSubject } from "rxjs";
 import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
-import { type Participant as LivekitParticipant } from "livekit-client";
+import { type RemoteParticipant } from "livekit-client";
 import { logger } from "matrix-js-sdk/lib/logger";
 
 import { Epoch, mapEpoch, ObservableScope } from "../../ObservableScope.ts";
@@ -201,23 +201,20 @@ describe("connections$ stream", () => {
 
 describe("connectionManagerData$ stream", () => {
   // Used in test to control fake connections' remoteParticipantsWithTracks$ streams
-  let fakePublishingParticipantsStreams: Map<
-    string,
-    Behavior<LivekitParticipant[]>
-  >;
+  let fakeRemoteParticipantsStreams: Map<string, Behavior<RemoteParticipant[]>>;
 
   function keyForTransport(transport: LivekitTransport): string {
     return `${transport.livekit_service_url}|${transport.livekit_alias}`;
   }
 
   beforeEach(() => {
-    fakePublishingParticipantsStreams = new Map();
+    fakeRemoteParticipantsStreams = new Map();
 
-    function getPublishingParticipantsFor(
+    function getRemoteParticipantsFor(
       transport: LivekitTransport,
-    ): Behavior<LivekitParticipant[]> {
+    ): Behavior<RemoteParticipant[]> {
       return (
-        fakePublishingParticipantsStreams.get(keyForTransport(transport)) ??
+        fakeRemoteParticipantsStreams.get(keyForTransport(transport)) ??
         new BehaviorSubject([])
       );
     }
@@ -227,13 +224,12 @@ describe("connectionManagerData$ stream", () => {
       .fn()
       .mockImplementation(
         (transport: LivekitTransport, scope: ObservableScope) => {
-          const fakePublishingParticipants$ = new BehaviorSubject<
-            LivekitParticipant[]
+          const fakeRemoteParticipants$ = new BehaviorSubject<
+            RemoteParticipant[]
           >([]);
           const mockConnection = {
             transport,
-            remoteParticipantsWithTracks$:
-              getPublishingParticipantsFor(transport),
+            remoteParticipantsWithTracks$: getRemoteParticipantsFor(transport),
           } as unknown as Connection;
           vi.mocked(mockConnection).start = vi.fn();
           vi.mocked(mockConnection).stop = vi.fn();
@@ -242,36 +238,36 @@ describe("connectionManagerData$ stream", () => {
             void mockConnection.stop();
           });
 
-          fakePublishingParticipantsStreams.set(
+          fakeRemoteParticipantsStreams.set(
             keyForTransport(transport),
-            fakePublishingParticipants$,
+            fakeRemoteParticipants$,
           );
           return mockConnection;
         },
       );
   });
 
-  test("Should report connections with the publishing participants", () => {
+  test("Should report connections with the remote participants", () => {
     withTestScheduler(({ expectObservable, schedule, behavior }) => {
       // Setup the fake participants streams behavior
       // ==============================
-      fakePublishingParticipantsStreams.set(
+      fakeRemoteParticipantsStreams.set(
         keyForTransport(TRANSPORT_1),
         behavior("oa-b", {
           o: [],
-          a: [{ identity: "user1A" } as LivekitParticipant],
+          a: [{ identity: "user1A" } as RemoteParticipant],
           b: [
-            { identity: "user1A" } as LivekitParticipant,
-            { identity: "user1B" } as LivekitParticipant,
+            { identity: "user1A" } as RemoteParticipant,
+            { identity: "user1B" } as RemoteParticipant,
           ],
         }),
       );
 
-      fakePublishingParticipantsStreams.set(
+      fakeRemoteParticipantsStreams.set(
         keyForTransport(TRANSPORT_2),
         behavior("o-a", {
           o: [],
-          a: [{ identity: "user2A" } as LivekitParticipant],
+          a: [{ identity: "user2A" } as RemoteParticipant],
         }),
       );
       // ==============================
diff --git a/src/state/CallViewModel/remoteMembers/ConnectionManager.ts b/src/state/CallViewModel/remoteMembers/ConnectionManager.ts
index 755ba3dd..6c2d64e0 100644
--- a/src/state/CallViewModel/remoteMembers/ConnectionManager.ts
+++ b/src/state/CallViewModel/remoteMembers/ConnectionManager.ts
@@ -12,7 +12,7 @@ import {
 } from "matrix-js-sdk/lib/matrixrtc";
 import { combineLatest, map, of, switchMap, tap } from "rxjs";
 import { type Logger } from "matrix-js-sdk/lib/logger";
-import { type LocalParticipant, type RemoteParticipant } from "livekit-client";
+import { type RemoteParticipant } from "livekit-client";
 
 import { type Behavior } from "../../Behavior.ts";
 import { type Connection } from "./Connection.ts";
@@ -22,17 +22,12 @@ import { areLivekitTransportsEqual } from "./MatrixLivekitMembers.ts";
 import { type ConnectionFactory } from "./ConnectionFactory.ts";
 
 export class ConnectionManagerData {
-  private readonly store: Map<
-    string,
-    [Connection, (LocalParticipant | RemoteParticipant)[]]
-  > = new Map();
+  private readonly store: Map<string, [Connection, RemoteParticipant[]]> =
+    new Map();
 
   public constructor() {}
 
-  public add(
-    connection: Connection,
-    participants: (LocalParticipant | RemoteParticipant)[],
-  ): void {
+  public add(connection: Connection, participants: RemoteParticipant[]): void {
     const key = this.getKey(connection.transport);
     const existing = this.store.get(key);
     if (!existing) {
@@ -58,7 +53,7 @@ export class ConnectionManagerData {
 
   public getParticipantForTransport(
     transport: LivekitTransport,
-  ): (LocalParticipant | RemoteParticipant)[] {
+  ): RemoteParticipant[] {
     const key = transport.livekit_service_url + "|" + transport.livekit_alias;
     return this.store.get(key)?.[1] ?? [];
   }
@@ -172,23 +167,24 @@ export function createConnectionManager$({
         const epoch = connections.epoch;
 
         // Map the connections to list of {connection, participants}[]
-        const listOfConnectionsWithPublishingParticipants =
-          connections.value.map((connection) => {
+        const listOfConnectionsWithRemoteParticipants = connections.value.map(
+          (connection) => {
             return connection.remoteParticipantsWithTracks$.pipe(
               map((participants) => ({
                 connection,
                 participants,
               })),
             );
-          });
+          },
+        );
 
         // probably not required
-        if (listOfConnectionsWithPublishingParticipants.length === 0) {
+        if (listOfConnectionsWithRemoteParticipants.length === 0) {
           return of(new Epoch(new ConnectionManagerData(), epoch));
         }
 
         // combineLatest the several streams into a single stream with the ConnectionManagerData
-        return combineLatest(listOfConnectionsWithPublishingParticipants).pipe(
+        return combineLatest(listOfConnectionsWithRemoteParticipants).pipe(
           map(
             (lists) =>
               new Epoch(
diff --git a/src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.test.ts b/src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.test.ts
index e675f723..77c00015 100644
--- a/src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.test.ts
+++ b/src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.test.ts
@@ -15,7 +15,7 @@ import { combineLatest, map, type Observable } from "rxjs";
 
 import { type IConnectionManager } from "./ConnectionManager.ts";
 import {
-  type MatrixLivekitMember,
+  type RemoteMatrixLivekitMember,
   createMatrixLivekitMembers$,
 } from "./MatrixLivekitMembers.ts";
 import {
@@ -100,12 +100,12 @@ test("should signal participant not yet connected to livekit", () => {
     });
 
     expectObservable(matrixLivekitMember$.pipe(map((e) => e.value))).toBe("a", {
-      a: expect.toSatisfy((data: MatrixLivekitMember[]) => {
+      a: expect.toSatisfy((data: RemoteMatrixLivekitMember[]) => {
         expect(data.length).toEqual(1);
         expectObservable(data[0].membership$).toBe("a", {
           a: bobMembership,
         });
-        expectObservable(data[0].participant$).toBe("a", {
+        expectObservable(data[0].participant.value$).toBe("a", {
           a: null,
         });
         expectObservable(data[0].connection$).toBe("a", {
@@ -180,12 +180,12 @@ test("should signal participant on a connection that is publishing", () => {
     });
 
     expectObservable(matrixLivekitMember$.pipe(map((e) => e.value))).toBe("a", {
-      a: expect.toSatisfy((data: MatrixLivekitMember[]) => {
+      a: expect.toSatisfy((data: RemoteMatrixLivekitMember[]) => {
         expect(data.length).toEqual(1);
         expectObservable(data[0].membership$).toBe("a", {
           a: bobMembership,
         });
-        expectObservable(data[0].participant$).toBe("a", {
+        expectObservable(data[0].participant.value$).toBe("a", {
           a: expect.toSatisfy((participant) => {
             expect(participant).toBeDefined();
             expect(participant!.identity).toEqual(bobParticipantId);
@@ -231,12 +231,12 @@ test("should signal participant on a connection that is not publishing", () => {
     });
 
     expectObservable(matrixLivekitMember$.pipe(map((e) => e.value))).toBe("a", {
-      a: expect.toSatisfy((data: MatrixLivekitMember[]) => {
+      a: expect.toSatisfy((data: RemoteMatrixLivekitMember[]) => {
         expect(data.length).toEqual(1);
         expectObservable(data[0].membership$).toBe("a", {
           a: bobMembership,
         });
-        expectObservable(data[0].participant$).toBe("a", {
+        expectObservable(data[0].participant.value$).toBe("a", {
           a: null,
         });
         expectObservable(data[0].connection$).toBe("a", {
@@ -296,7 +296,7 @@ describe("Publication edge case", () => {
       expectObservable(matrixLivekitMember$.pipe(map((e) => e.value))).toBe(
         "a",
         {
-          a: expect.toSatisfy((data: MatrixLivekitMember[]) => {
+          a: expect.toSatisfy((data: RemoteMatrixLivekitMember[]) => {
             expect(data.length).toEqual(2);
             expectObservable(data[0].membership$).toBe("a", {
               a: bobMembership,
@@ -305,7 +305,7 @@ describe("Publication edge case", () => {
               // The real connection should be from transportA as per the membership
               a: connectionA,
             });
-            expectObservable(data[0].participant$).toBe("a", {
+            expectObservable(data[0].participant.value$).toBe("a", {
               a: expect.toSatisfy((participant) => {
                 expect(participant).toBeDefined();
                 expect(participant!.identity).toEqual(bobParticipantId);
@@ -362,7 +362,7 @@ describe("Publication edge case", () => {
       expectObservable(matrixLivekitMember$.pipe(map((e) => e.value))).toBe(
         "a",
         {
-          a: expect.toSatisfy((data: MatrixLivekitMember[]) => {
+          a: expect.toSatisfy((data: RemoteMatrixLivekitMember[]) => {
             expect(data.length).toEqual(2);
             expectObservable(data[0].membership$).toBe("a", {
               a: bobMembership,
@@ -371,7 +371,7 @@ describe("Publication edge case", () => {
               // The real connection should be from transportA as per the membership
               a: connectionA,
             });
-            expectObservable(data[0].participant$).toBe("a", {
+            expectObservable(data[0].participant.value$).toBe("a", {
               // No participant as Bob is not publishing on his membership transport
               a: null,
             });
diff --git a/src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.ts b/src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.ts
index 79ad933c..4cca0d5b 100644
--- a/src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.ts
+++ b/src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.ts
@@ -5,10 +5,7 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */
 
-import {
-  type LocalParticipant as LocalLivekitParticipant,
-  type RemoteParticipant as RemoteLivekitParticipant,
-} from "livekit-client";
+import { type LocalParticipant, type RemoteParticipant } from "livekit-client";
 import {
   type LivekitTransport,
   type CallMembership,
@@ -24,22 +21,44 @@ import { generateItemsWithEpoch } from "../../../utils/observable";
 
 const logger = rootLogger.getChild("[MatrixLivekitMembers]");
 
-/**
- * Represents a Matrix call member and their associated LiveKit participation.
- * `livekitParticipant` can be undefined if the member is not yet connected to the livekit room
- * or if it has no livekit transport at all.
- */
-export interface MatrixLivekitMember {
+interface LocalTaggedParticipant {
+  type: "local";
+  value$: Behavior<LocalParticipant | null>;
+}
+interface RemoteTaggedParticipant {
+  type: "remote";
+  value$: Behavior<RemoteParticipant | null>;
+}
+export type TaggedParticipant =
+  | LocalTaggedParticipant
+  | RemoteTaggedParticipant;
+
+interface MatrixLivekitMember {
   membership$: Behavior<CallMembership>;
-  participant$: Behavior<
-    LocalLivekitParticipant | RemoteLivekitParticipant | null
-  >;
   connection$: Behavior<Connection | null>;
   // participantId: string; We do not want a participantId here since it will be generated by the jwt
   // TODO decide if we can also drop the userId. Its in the matrix membership anyways.
   userId: string;
 }
 
+/**
+ * Represents the local Matrix call member and their associated LiveKit participation.
+ * `livekitParticipant` can be null if the member is not yet connected to the livekit room
+ * or if it has no livekit transport at all.
+ */
+export interface LocalMatrixLivekitMember extends MatrixLivekitMember {
+  participant: LocalTaggedParticipant;
+}
+
+/**
+ * Represents a remote Matrix call member and their associated LiveKit participation.
+ * `livekitParticipant` can be null if the member is not yet connected to the livekit room
+ * or if it has no livekit transport at all.
+ */
+export interface RemoteMatrixLivekitMember extends MatrixLivekitMember {
+  participant: RemoteTaggedParticipant;
+}
+
 interface Props {
   scope: ObservableScope;
   membershipsWithTransport$: Behavior<
@@ -61,7 +80,7 @@ export function createMatrixLivekitMembers$({
   scope,
   membershipsWithTransport$,
   connectionManager,
-}: Props): Behavior<Epoch<MatrixLivekitMember[]>> {
+}: Props): Behavior<Epoch<RemoteMatrixLivekitMember[]>> {
   /**
    * Stream of all the call members and their associated livekit data (if available).
    */
@@ -110,12 +129,14 @@ export function createMatrixLivekitMembers$({
           logger.debug(
             `Generating member for participantId: ${participantId}, userId: ${userId}`,
           );
+          const { participant$, ...rest } = scope.splitBehavior(data$);
           // will only get called once per `participantId, userId` pair.
           // updates to data$ and as a result to displayName$ and mxcAvatarUrl$ are more frequent.
           return {
             participantId,
             userId,
-            ...scope.splitBehavior(data$),
+            participant: { type: "remote" as const, value$: participant$ },
+            ...rest,
           };
         },
       ),
diff --git a/src/state/CallViewModel/remoteMembers/integration.test.ts b/src/state/CallViewModel/remoteMembers/integration.test.ts
index e3aa6be8..2c3591a5 100644
--- a/src/state/CallViewModel/remoteMembers/integration.test.ts
+++ b/src/state/CallViewModel/remoteMembers/integration.test.ts
@@ -29,7 +29,7 @@ import { type ProcessorState } from "../../../livekit/TrackProcessorContext.tsx"
 import {
   areLivekitTransportsEqual,
   createMatrixLivekitMembers$,
-  type MatrixLivekitMember,
+  type RemoteMatrixLivekitMember,
 } from "./MatrixLivekitMembers.ts";
 import { createConnectionManager$ } from "./ConnectionManager.ts";
 import { membershipsAndTransports$ } from "../../SessionBehaviors.ts";
@@ -132,7 +132,7 @@ test("bob, carl, then bob joining no tracks yet", () => {
     });
 
     expectObservable(matrixLivekitItems$).toBe(vMarble, {
-      a: expect.toSatisfy((e: Epoch<MatrixLivekitMember[]>) => {
+      a: expect.toSatisfy((e: Epoch<RemoteMatrixLivekitMember[]>) => {
         const items = e.value;
         expect(items.length).toBe(1);
         const item = items[0]!;
@@ -147,12 +147,12 @@ test("bob, carl, then bob joining no tracks yet", () => {
             ),
           ),
         });
-        expectObservable(item.participant$).toBe("a", {
+        expectObservable(item.participant.value$).toBe("a", {
           a: null,
         });
         return true;
       }),
-      b: expect.toSatisfy((e: Epoch<MatrixLivekitMember[]>) => {
+      b: expect.toSatisfy((e: Epoch<RemoteMatrixLivekitMember[]>) => {
         const items = e.value;
         expect(items.length).toBe(2);
 
@@ -161,7 +161,7 @@ test("bob, carl, then bob joining no tracks yet", () => {
           expectObservable(item.membership$).toBe("a", {
             a: bobMembership,
           });
-          expectObservable(item.participant$).toBe("a", {
+          expectObservable(item.participant.value$).toBe("a", {
             a: null,
           });
         }
@@ -172,7 +172,7 @@ test("bob, carl, then bob joining no tracks yet", () => {
           expectObservable(item.membership$).toBe("a", {
             a: carlMembership,
           });
-          expectObservable(item.participant$).toBe("a", {
+          expectObservable(item.participant.value$).toBe("a", {
             a: null,
           });
           expectObservable(item.connection$).toBe("a", {
@@ -189,7 +189,7 @@ test("bob, carl, then bob joining no tracks yet", () => {
         }
         return true;
       }),
-      c: expect.toSatisfy((e: Epoch<MatrixLivekitMember[]>) => {
+      c: expect.toSatisfy((e: Epoch<RemoteMatrixLivekitMember[]>) => {
         const items = e.value;
         expect(items.length).toBe(3);
 
@@ -216,7 +216,7 @@ test("bob, carl, then bob joining no tracks yet", () => {
               return true;
             }),
           });
-          expectObservable(item.participant$).toBe("a", {
+          expectObservable(item.participant.value$).toBe("a", {
             a: null,
           });
         }
diff --git a/src/state/CallViewModelWidget.test.ts b/src/state/CallViewModelWidget.test.ts
index afcf69ba..5d6442f1 100644
--- a/src/state/CallViewModelWidget.test.ts
+++ b/src/state/CallViewModelWidget.test.ts
@@ -15,6 +15,7 @@ import { constant } from "./Behavior.ts";
 import { aliceParticipant, localRtcMember } from "../utils/test-fixtures.ts";
 import { ElementWidgetActions, widget } from "../widget.ts";
 import { E2eeType } from "../e2ee/e2eeType.ts";
+import { MatrixRTCMode } from "../settings/settings.ts";
 
 vi.mock("@livekit/components-core", { spy: true });
 
@@ -34,36 +35,43 @@ vi.mock("../widget", () => ({
   },
 }));
 
-it("expect leave when ElementWidgetActions.HangupCall is called", async () => {
-  const pr = Promise.withResolvers<string>();
-  withCallViewModel(
-    {
-      remoteParticipants$: constant([aliceParticipant]),
-      rtcMembers$: constant([localRtcMember]),
-    },
-    (vm: CallViewModel) => {
-      vm.leave$.subscribe((s: string) => {
-        pr.resolve(s);
-      });
+it.each([
+  [MatrixRTCMode.Legacy],
+  [MatrixRTCMode.Compatibil],
+  [MatrixRTCMode.Matrix_2_0],
+])(
+  "expect leave when ElementWidgetActions.HangupCall is called (%s mode)",
+  async (mode) => {
+    const pr = Promise.withResolvers<string>();
+    withCallViewModel(mode)(
+      {
+        remoteParticipants$: constant([aliceParticipant]),
+        rtcMembers$: constant([localRtcMember]),
+      },
+      (vm: CallViewModel) => {
+        vm.leave$.subscribe((s: string) => {
+          pr.resolve(s);
+        });
 
-      widget!.lazyActions!.emit(
-        ElementWidgetActions.HangupCall,
-        new CustomEvent(ElementWidgetActions.HangupCall, {
-          detail: {
-            action: "im.vector.hangup",
-            api: "toWidget",
-            data: {},
-            requestId: "widgetapi-1761237395918",
-            widgetId: "mrUjS9T6uKUOWHMxXvLbSv0F",
-          },
-        }),
-      );
-    },
-    {
-      encryptionSystem: { kind: E2eeType.PER_PARTICIPANT },
-    },
-  );
+        widget!.lazyActions!.emit(
+          ElementWidgetActions.HangupCall,
+          new CustomEvent(ElementWidgetActions.HangupCall, {
+            detail: {
+              action: "im.vector.hangup",
+              api: "toWidget",
+              data: {},
+              requestId: "widgetapi-1761237395918",
+              widgetId: "mrUjS9T6uKUOWHMxXvLbSv0F",
+            },
+          }),
+        );
+      },
+      {
+        encryptionSystem: { kind: E2eeType.PER_PARTICIPANT },
+      },
+    );
 
-  const source = await pr.promise;
-  expect(source).toBe("user");
-});
+    const source = await pr.promise;
+    expect(source).toBe("user");
+  },
+);
diff --git a/src/state/UserMedia.ts b/src/state/UserMedia.ts
index 38f22122..690870e6 100644
--- a/src/state/UserMedia.ts
+++ b/src/state/UserMedia.ts
@@ -27,6 +27,7 @@ import type { ReactionOption } from "../reactions";
 import { observeSpeaker$ } from "./observeSpeaker.ts";
 import { generateItems } from "../utils/observable.ts";
 import { ScreenShare } from "./ScreenShare.ts";
+import { type TaggedParticipant } from "./CallViewModel/remoteMembers/MatrixLivekitMembers.ts";
 
 /**
  * Sorting bins defining the order in which media tiles appear in the layout.
@@ -68,40 +69,46 @@ enum SortingBin {
  * for inclusion in the call layout and tracks associated screen shares.
  */
 export class UserMedia {
-  public readonly vm: UserMediaViewModel = this.participant$.value?.isLocal
-    ? new LocalUserMediaViewModel(
-        this.scope,
-        this.id,
-        this.userId,
-        this.participant$ as Behavior<LocalParticipant | null>,
-        this.encryptionSystem,
-        this.livekitRoom$,
-        this.focusUrl$,
-        this.mediaDevices,
-        this.displayName$,
-        this.mxcAvatarUrl$,
-        this.scope.behavior(this.handRaised$),
-        this.scope.behavior(this.reaction$),
-      )
-    : new RemoteUserMediaViewModel(
-        this.scope,
-        this.id,
-        this.userId,
-        this.participant$ as Behavior<RemoteParticipant | null>,
-        this.encryptionSystem,
-        this.livekitRoom$,
-        this.focusUrl$,
-        this.pretendToBeDisconnected$,
-        this.displayName$,
-        this.mxcAvatarUrl$,
-        this.scope.behavior(this.handRaised$),
-        this.scope.behavior(this.reaction$),
-      );
+  public readonly vm: UserMediaViewModel =
+    this.participant.type === "local"
+      ? new LocalUserMediaViewModel(
+          this.scope,
+          this.id,
+          this.userId,
+          this.participant.value$,
+          this.encryptionSystem,
+          this.livekitRoom$,
+          this.focusUrl$,
+          this.mediaDevices,
+          this.displayName$,
+          this.mxcAvatarUrl$,
+          this.scope.behavior(this.handRaised$),
+          this.scope.behavior(this.reaction$),
+        )
+      : new RemoteUserMediaViewModel(
+          this.scope,
+          this.id,
+          this.userId,
+          this.participant.value$,
+          this.encryptionSystem,
+          this.livekitRoom$,
+          this.focusUrl$,
+          this.pretendToBeDisconnected$,
+          this.displayName$,
+          this.mxcAvatarUrl$,
+          this.scope.behavior(this.handRaised$),
+          this.scope.behavior(this.reaction$),
+        );
 
   private readonly speaker$ = this.scope.behavior(
     observeSpeaker$(this.vm.speaking$),
   );
 
+  // TypeScript needs this widening of the type to happen in a separate statement
+  private readonly participant$: Behavior<
+    LocalParticipant | RemoteParticipant | null
+  > = this.participant.value$;
+
   /**
    * All screen share media associated with this user media.
    */
@@ -184,9 +191,7 @@ export class UserMedia {
     private readonly scope: ObservableScope,
     public readonly id: string,
     private readonly userId: string,
-    private readonly participant$: Behavior<
-      LocalParticipant | RemoteParticipant | null
-    >,
+    private readonly participant: TaggedParticipant,
     private readonly encryptionSystem: EncryptionSystem,
     private readonly livekitRoom$: Behavior<LivekitRoom | undefined>,
     private readonly focusUrl$: Behavior<string | undefined>,
diff --git a/src/utils/observable.test.ts b/src/utils/observable.test.ts
index d1034e7b..be677367 100644
--- a/src/utils/observable.test.ts
+++ b/src/utils/observable.test.ts
@@ -5,11 +5,12 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */
 
-import { test } from "vitest";
-import { Subject } from "rxjs";
+import { expect, test } from "vitest";
+import { type Observable, of, Subject, switchMap } from "rxjs";
 
 import { withTestScheduler } from "./test";
-import { generateItems, pauseWhen } from "./observable";
+import { filterBehavior, generateItems, pauseWhen } from "./observable";
+import { type Behavior } from "../state/Behavior";
 
 test("pauseWhen", () => {
   withTestScheduler(({ behavior, expectObservable }) => {
@@ -72,3 +73,31 @@ test("generateItems", () => {
     expectObservable(scope4$).toBe(scope4Marbles);
   });
 });
+
+test("filterBehavior", () => {
+  withTestScheduler(({ behavior, expectObservable }) => {
+    // Filtering the input should segment it into 2 modes of non-null behavior.
+    const inputMarbles = "   abcxabx";
+    const filteredMarbles = "a--xa-x";
+
+    const input$ = behavior(inputMarbles, {
+      a: "a",
+      b: "b",
+      c: "c",
+      x: null,
+    });
+    const filtered$: Observable<Behavior<string> | null> = input$.pipe(
+      filterBehavior((value) => typeof value === "string"),
+    );
+
+    expectObservable(filtered$).toBe(filteredMarbles, {
+      a: expect.any(Object),
+      x: null,
+    });
+    expectObservable(
+      filtered$.pipe(
+        switchMap((value$) => (value$ === null ? of(null) : value$)),
+      ),
+    ).toBe(inputMarbles, { a: "a", b: "b", c: "c", x: null });
+  });
+});
diff --git a/src/utils/observable.ts b/src/utils/observable.ts
index 053921cd..a6dafea3 100644
--- a/src/utils/observable.ts
+++ b/src/utils/observable.ts
@@ -22,6 +22,7 @@ import {
   withLatestFrom,
   BehaviorSubject,
   type OperatorFunction,
+  distinctUntilChanged,
 } from "rxjs";
 
 import { type Behavior } from "../state/Behavior";
@@ -185,6 +186,28 @@ export function generateItemsWithEpoch<
   );
 }
 
+/**
+ * Segments a behavior into periods during which its value matches the filter
+ * (outputting a behavior with a narrowed type) and periods during which it does
+ * not match (outputting null).
+ */
+export function filterBehavior<T, S extends T>(
+  predicate: (value: T) => value is S,
+): OperatorFunction<T, Behavior<S> | null> {
+  return (input$) =>
+    input$.pipe(
+      scan<T, BehaviorSubject<S> | null>((acc$, input) => {
+        if (predicate(input)) {
+          const output$ = acc$ ?? new BehaviorSubject(input);
+          output$.next(input);
+          return output$;
+        }
+        return null;
+      }, null),
+      distinctUntilChanged(),
+    );
+}
+
 function generateItemsInternal<
   Input,
   Keys extends [unknown, ...unknown[]],
diff --git a/src/utils/test-viewmodel.ts b/src/utils/test-viewmodel.ts
index 98c45d86..0745be72 100644
--- a/src/utils/test-viewmodel.ts
+++ b/src/utils/test-viewmodel.ts
@@ -37,6 +37,7 @@ import {
 import { aliceRtcMember, localRtcMember } from "./test-fixtures";
 import { type RaisedHandInfo, type ReactionInfo } from "../reactions";
 import { constant } from "../state/Behavior";
+import { MatrixRTCMode } from "../settings/settings";
 
 mockConfig({ livekit: { livekit_service_url: "https://example.com" } });
 
@@ -162,6 +163,7 @@ export function getBasicCallViewModelEnvironment(
           setE2EEEnabled: async () => Promise.resolve(),
         }),
       connectionState$: constant(ConnectionState.Connected),
+      matrixRTCMode$: constant(MatrixRTCMode.Legacy),
       ...callViewModelOptions,
     },
     handRaisedSubject$,