diff --git a/lib/Signaling/BackendNotifier.php b/lib/Signaling/BackendNotifier.php
index 63597b1502b..fe884ee4b35 100644
--- a/lib/Signaling/BackendNotifier.php
+++ b/lib/Signaling/BackendNotifier.php
@@ -351,60 +351,70 @@ public function participantsModified(Room $room, array $sessionIds): void {
 	 * @param Room $room
 	 * @param int $flags
 	 * @param string[] $sessionIds
+	 * @param bool $changeAll
 	 * @throws \Exception
 	 */
-	public function roomInCallChanged(Room $room, int $flags, array $sessionIds): void {
-		$changed = [];
-		$users = [];
+	public function roomInCallChanged(Room $room, int $flags, array $sessionIds, bool $changeAll = false): void {
+		if ($changeAll) {
+			$data = [
+				'incall' => $flags,
+				'all' => true
+			];
+		} else {
+			$changed = [];
+			$users = [];
 
-		$participants = $this->participantService->getParticipantsForAllSessions($room);
-		foreach ($participants as $participant) {
-			$session = $participant->getSession();
-			if (!$session instanceof Session) {
-				continue;
-			}
+			$participants = $this->participantService->getParticipantsForAllSessions($room);
+			foreach ($participants as $participant) {
+				$session = $participant->getSession();
+				if (!$session instanceof Session) {
+					continue;
+				}
 
-			$attendee = $participant->getAttendee();
-			if ($attendee->getActorType() !== Attendee::ACTOR_USERS
-				&& $attendee->getActorType() !== Attendee::ACTOR_GUESTS) {
-				continue;
-			}
+				$attendee = $participant->getAttendee();
+				if ($attendee->getActorType() !== Attendee::ACTOR_USERS
+					&& $attendee->getActorType() !== Attendee::ACTOR_GUESTS) {
+					continue;
+				}
 
-			$data = [
-				'inCall' => $session->getInCall(),
-				'lastPing' => $session->getLastPing(),
-				'sessionId' => $session->getSessionId(),
-				'nextcloudSessionId' => $session->getSessionId(),
-				'participantType' => $attendee->getParticipantType(),
-				'participantPermissions' => $participant->getPermissions(),
-			];
-			if ($attendee->getActorType() === Attendee::ACTOR_USERS) {
-				$data['userId'] = $attendee->getActorId();
-			}
+				$data = [
+					'inCall' => $session->getInCall(),
+					'lastPing' => $session->getLastPing(),
+					'sessionId' => $session->getSessionId(),
+					'nextcloudSessionId' => $session->getSessionId(),
+					'participantType' => $attendee->getParticipantType(),
+					'participantPermissions' => $participant->getPermissions(),
+				];
+				if ($attendee->getActorType() === Attendee::ACTOR_USERS) {
+					$data['userId'] = $attendee->getActorId();
+				}
 
-			if ($session->getInCall() !== Participant::FLAG_DISCONNECTED) {
-				$users[] = $data;
-			}
+				if ($session->getInCall() !== Participant::FLAG_DISCONNECTED) {
+					$users[] = $data;
+				}
 
-			if (\in_array($session->getSessionId(), $sessionIds, true)) {
-				$changed[] = $data;
+				if (\in_array($session->getSessionId(), $sessionIds, true)) {
+					$changed[] = $data;
+				}
 			}
+
+			$data = [
+				'incall' => $flags,
+				'changed' => $changed,
+				'users' => $users,
+			];
 		}
 
 		$start = microtime(true);
 		$this->backendRequest($room, [
 			'type' => 'incall',
-			'incall' => [
-				'incall' => $flags,
-				'changed' => $changed,
-				'users' => $users
-			],
+			'incall' => $data,
 		]);
 		$duration = microtime(true) - $start;
 		$this->logger->debug('Room in-call status changed: {token} {flags} {users} ({duration})', [
 			'token' => $room->getToken(),
 			'flags' => $flags,
-			'users' => print_r($sessionIds, true),
+			'users' => $changeAll ? 'all' : print_r($sessionIds, true),
 			'duration' => sprintf('%.2f', $duration),
 			'app' => 'spreed-hpb',
 		]);
diff --git a/lib/Signaling/Listener.php b/lib/Signaling/Listener.php
index 26af22371ec..bae1749ac96 100644
--- a/lib/Signaling/Listener.php
+++ b/lib/Signaling/Listener.php
@@ -318,7 +318,8 @@ protected static function registerExternalSignaling(IEventDispatcher $dispatcher
 			$notifier->roomInCallChanged(
 				$event->getRoom(),
 				$event->getNewValue(),
-				$sessionIds
+				[],
+				true
 			);
 		});
 
diff --git a/lib/Signaling/Manager.php b/lib/Signaling/Manager.php
index 23f6048532a..a6dacceaf63 100644
--- a/lib/Signaling/Manager.php
+++ b/lib/Signaling/Manager.php
@@ -49,7 +49,8 @@ public function isCompatibleSignalingServer(IResponse $response): bool {
 		$featureHeader = $response->getHeader(self::FEATURE_HEADER);
 		$features = explode(',', $featureHeader);
 		$features = array_map('trim', $features);
-		return in_array('audio-video-permissions', $features, true);
+		return in_array('audio-video-permissions', $features, true)
+			&& in_array('incall-all', $features, true);
 	}
 
 	public function getSignalingServerLinkForConversation(?Room $room): string {
diff --git a/src/utils/signaling.js b/src/utils/signaling.js
index c0d1fbb52d4..6a47b99e4fd 100644
--- a/src/utils/signaling.js
+++ b/src/utils/signaling.js
@@ -977,7 +977,7 @@ Signaling.Standalone.prototype.helloResponseReceived = function(data) {
 		}
 	}
 
-	if (!this.hasFeature('audio-video-permissions')) {
+	if (!this.hasFeature('audio-video-permissions') || !this.hasFeature('incall-all')) {
 		showError(
 			t('spreed', 'The configured signaling server needs to be updated to be compatible with this version of Talk. Please contact your administrator.'),
 			{
@@ -1280,7 +1280,17 @@ Signaling.Standalone.prototype.processRoomListEvent = function(data) {
 Signaling.Standalone.prototype.processRoomParticipantsEvent = function(data) {
 	switch (data.event.type) {
 	case 'update':
-		this._trigger('usersChanged', [data.event.update.users || []])
+		if (data.event.update.all) {
+			// With `"all": true`
+			if (data.event.update.incall === 0) {
+				this._trigger('allUsersChangedInCallToDisconnected')
+			} else {
+				console.error('Unknown room participant event', data)
+			}
+		} else {
+			// With updated user list
+			this._trigger('usersChanged', [data.event.update.users || []])
+		}
 		this._trigger('participantListChanged')
 		break
 	case 'flags':
diff --git a/src/utils/webrtc/webrtc.js b/src/utils/webrtc/webrtc.js
index 49d26814721..99a6a9079d3 100644
--- a/src/utils/webrtc/webrtc.js
+++ b/src/utils/webrtc/webrtc.js
@@ -543,6 +543,15 @@ export default function initWebRtc(signaling, _callParticipantCollection, _local
 		})
 		usersInCallChanged(signaling, usersInCallMapping)
 	})
+	signaling.on('allUsersChangedInCallToDisconnected', function() {
+		if (!localUserInCall) {
+			return
+		}
+
+		// "End meeting for all" was used, we don't have a user list but everyone disconnects from the call
+		usersInCallMapping = {}
+		usersInCallChanged(signaling, usersInCallMapping)
+	})
 	signaling.on('participantFlagsChanged', function(event) {
 		/**
 		 * event {