diff --git a/lib/Controller/RoomController.php b/lib/Controller/RoomController.php
index ba1ee4b1ae2..e45a1a3da19 100644
--- a/lib/Controller/RoomController.php
+++ b/lib/Controller/RoomController.php
@@ -1505,6 +1505,15 @@ public function setReadOnly(int $state): DataResponse {
 			return new DataResponse([], Http::STATUS_BAD_REQUEST);
 		}
 
+		if ($state === Room::READ_ONLY) {
+			$participants = $this->participantService->getParticipantsInCall($this->room);
+
+			// kick out all participants out of the call
+			foreach ($participants as $participant) {
+				$this->participantService->changeInCall($this->room, $participant, Participant::FLAG_DISCONNECTED);
+			}
+		}
+
 		return new DataResponse();
 	}
 
diff --git a/lib/Service/ParticipantService.php b/lib/Service/ParticipantService.php
index 4ad4206d643..d971535822f 100644
--- a/lib/Service/ParticipantService.php
+++ b/lib/Service/ParticipantService.php
@@ -474,6 +474,10 @@ public function changeInCall(Room $room, Participant $participant, int $flags):
 			return;
 		}
 
+		if ($session->getInCall() === $flags) {
+			return;
+		}
+
 		$event = new ModifyParticipantEvent($room, $participant, 'inCall', $flags, $session->getInCall());
 		if ($flags !== Participant::FLAG_DISCONNECTED) {
 			$this->dispatcher->dispatch(Room::EVENT_BEFORE_SESSION_JOIN_CALL, $event);
diff --git a/src/components/ConversationSettings/LobbySettings.vue b/src/components/ConversationSettings/LobbySettings.vue
index c7300838098..7bfced8ff9d 100644
--- a/src/components/ConversationSettings/LobbySettings.vue
+++ b/src/components/ConversationSettings/LobbySettings.vue
@@ -25,6 +25,9 @@
 			<div id="moderation_settings_enable_lobby_hint" class="app-settings-section__hint">
 				{{ t('spreed', 'Enabling the lobby only allows moderators to post messages.') }}
 			</div>
+			<div v-if="hasCall" class="app-settings-section__hint">
+				{{ t('spreed', 'This will also remove non-moderators from the ongoing call.') }}
+			</div>
 			<div>
 				<input id="moderation_settings_enable_lobby_checkbox"
 					aria-describedby="moderation_settings_enable_lobby_hint"
@@ -93,6 +96,10 @@ export default {
 	},
 
 	computed: {
+		hasCall() {
+			return this.conversation.hasCall
+		},
+
 		conversation() {
 			return this.$store.getters.conversation(this.token) || this.$store.getters.dummyConversation
 		},
diff --git a/src/components/ConversationSettings/LockingSettings.vue b/src/components/ConversationSettings/LockingSettings.vue
index 758c4a7e99c..cf060ac7383 100644
--- a/src/components/ConversationSettings/LockingSettings.vue
+++ b/src/components/ConversationSettings/LockingSettings.vue
@@ -24,6 +24,9 @@
 		<div id="moderation_settings_lock_conversation_hint" class="app-settings-section__hint">
 			{{ t('spreed', 'Locking the conversation prevents anyone to post messages or start calls.') }}
 		</div>
+		<div v-if="hasCall" class="app-settings-section__hint">
+			{{ t('spreed', 'This will also terminate the ongoing call.') }}
+		</div>
 		<div>
 			<input id="moderation_settings_lock_conversation_checkbox"
 				aria-describedby="moderation_settings_lock_conversation_hint"
@@ -59,6 +62,10 @@ export default {
 	},
 
 	computed: {
+		hasCall() {
+			return this.conversation.hasCall
+		},
+
 		conversation() {
 			return this.$store.getters.conversation(this.token) || this.$store.getters.dummyConversation
 		},