diff --git a/lib/model/message.dart b/lib/model/message.dart
index 90a0c28840..936bc3bb1f 100644
--- a/lib/model/message.dart
+++ b/lib/model/message.dart
@@ -408,29 +408,87 @@ class MessageStoreImpl extends HasChannelStore with MessageStore, _OutboxMessage
 
   void reconcileMessages(List<Message> messages) {
     assert(!_disposed);
-    // What to do when some of the just-fetched messages are already known?
+    for (int i = 0; i < messages.length; i++) {
+      final message = messages[i];
+      messages[i] = this.messages.update(message.id,
+        ifAbsent: () => _reconcileUnrecognizedMessage(message),
+        (current) => _reconcileRecognizedMessage(current, message));
+    }
+  }
+
+  Message _reconcileUnrecognizedMessage(Message incoming) {
+    if (
+      incoming is StreamMessage
+      && subscriptions[incoming.streamId] == null
+    ) {
+      // The message is in an unsubscribed channel. It might grow stale;
+      // add it to _maybeStaleChannelMessages.
+      _maybeStaleChannelMessages.add(incoming.id);
+    }
+    return _stripMatchFields(incoming);
+  }
+
+  Message _reconcileRecognizedMessage(Message current, Message incoming) {
+    // This just-fetched message is one we already know about.
     // This is common and normal: in particular it happens when one message list
     // overlaps another, e.g. a stream and a topic within it.
     //
     // Most often, the just-fetched message will look just like the one we
-    // already have.  But they can differ: message fetching happens out of band
-    // from the event queue, so there's inherently a race.
-    //
-    // If the fetched message reflects changes we haven't yet heard from the
-    // event queue, then it doesn't much matter which version we use: we'll
-    // soon get the corresponding events and apply the changes anyway.
-    // But if it lacks changes we've already heard from the event queue, then
-    // we won't hear those events again; the only way to wind up with an
-    // updated message is to use the version we have, that already reflects
-    // those events' changes.  So we always stick with the version we have.
-    for (int i = 0; i < messages.length; i++) {
-      final message = messages[i];
-      messages[i] = this.messages.putIfAbsent(message.id, () {
-        message.matchContent = null;
-        message.matchTopic = null;
-        return message;
-      });
+    // already have. But not always, and we can choose intelligently whether
+    // to keep the stored version or clobber it with the incoming one.
+
+    bool currentIsMaybeStale = false;
+    if (incoming is StreamMessage) {
+      if (subscriptions[incoming.streamId] != null) {
+        // The incoming version won't grow stale; it's in a subscribed channel.
+        // Remove it from _maybeStaleChannelMessages if it was there.
+        currentIsMaybeStale = _maybeStaleChannelMessages.remove(incoming.id);
+      } else {
+        assert(_maybeStaleChannelMessages.contains(incoming.id));
+        currentIsMaybeStale = true;
+      }
     }
+
+    if (currentIsMaybeStale) {
+      // The event queue is unreliable for this message; the message was in an
+      // unsubscribed channel when we stored it or sometime since, so the stored
+      // version might be stale. Refresh it with the fetched version.
+      return _stripMatchFields(incoming);
+    } else {
+      // Message fetching happens out of band from the event queue, so there's
+      // inherently a race.
+      //
+      // If the fetched message reflects changes we haven't yet heard from the
+      // event queue, then it doesn't much matter which version we use: we'll
+      // soon get the corresponding events and apply the changes anyway.
+      // But if it lacks changes we've already heard from the event queue, then
+      // we won't hear those events again; the only way to wind up with an
+      // updated message is to use the version we have, that already reflects
+      // those events' changes.  So, stick with the version we have.
+      return current;
+    }
+  }
+
+  /// Messages in [messages] whose data stream is or was presumably broken
+  /// by the message being in an unsubscribed channel.
+  ///
+  /// This is the subset of [messages] where the message was
+  /// in an unsubscribed channel when we added it or sometime since.
+  ///
+  /// We don't expect update events for messages in unsubscribed channels,
+  /// so if some of these maybe-stale messages appear in a fetch,
+  /// we'll always clobber our stored version with the fetched version.
+  /// See [reconcileMessages].
+  ///
+  /// (We have seen a few such events, actually --
+  /// maybe because the channel only recently became unsubscribed? --
+  /// but not consistently, and we're not supposed to rely on them.)
+  final Set<int> _maybeStaleChannelMessages = {};
+
+  Message _stripMatchFields(Message message) {
+    message.matchContent = null;
+    message.matchTopic = null;
+    return message;
   }
 
   @override
@@ -497,6 +555,30 @@ class MessageStoreImpl extends HasChannelStore with MessageStore, _OutboxMessage
     );
   }
 
+  void handleChannelDeleteEvent(ChannelDeleteEvent event) {
+    final channelIds = event.streams.map((channel) => channel.streamId);
+    _handleSubscriptionsRemoved(channelIds);
+  }
+
+  void handleSubscriptionRemoveEvent(SubscriptionRemoveEvent event) {
+    _handleSubscriptionsRemoved(event.streamIds);
+  }
+
+  void _handleSubscriptionsRemoved(Iterable<int> channelIds) {
+    if (channelIds.length > 8) {
+      assert(channelIds is! Set);
+      // optimization: https://github.com/zulip/zulip-flutter/pull/1912#discussion_r2479350329
+      channelIds = Set.from(channelIds);
+    }
+
+    // Linear in [messages].
+    final affectedKnownMessageIds = messages.values
+      .where((message) => message is StreamMessage && channelIds.contains(message.streamId))
+      .map((message) => message.id);
+
+    _maybeStaleChannelMessages.addAll(affectedKnownMessageIds);
+  }
+
   void handleUserTopicEvent(UserTopicEvent event) {
     for (final view in _messageListViews) {
       view.handleUserTopicEvent(event);
@@ -510,10 +592,18 @@ class MessageStoreImpl extends HasChannelStore with MessageStore, _OutboxMessage
   }
 
   void handleMessageEvent(MessageEvent event) {
+    final message = event.message;
+
     // If the message is one we already know about (from a fetch),
     // clobber it with the one from the event system.
-    // See [fetchedMessages] for reasoning.
-    messages[event.message.id] = event.message;
+    // See [reconcileMessages] for reasoning.
+    messages[message.id] = message;
+
+    if (message is StreamMessage && subscriptions[message.streamId] == null) {
+      // We didn't expect this event, because the channel is unsubscribed. But
+      // that doesn't mean we should expect future events about this message.
+      _maybeStaleChannelMessages.add(message.id);
+    }
 
     _handleMessageEventOutbox(event);
 
@@ -602,6 +692,12 @@ class MessageStoreImpl extends HasChannelStore with MessageStore, _OutboxMessage
         // See [StreamConversation.displayRecipient] on why the invalidation is
         // needed.
         message.conversation.displayRecipient = null;
+
+        if (subscriptions[newStreamId] == null) {
+          // The message was moved into an unsubscribed channel, which means
+          // we expect our data on it to get stale.
+          _maybeStaleChannelMessages.add(messageId);
+        }
       }
 
       if (newTopic != origTopic) {
@@ -624,6 +720,7 @@ class MessageStoreImpl extends HasChannelStore with MessageStore, _OutboxMessage
   void handleDeleteMessageEvent(DeleteMessageEvent event) {
     for (final messageId in event.messageIds) {
       messages.remove(messageId);
+      _maybeStaleChannelMessages.remove(messageId);
       _editMessageRequests.remove(messageId);
     }
     for (final view in _messageListViews) {
diff --git a/lib/model/store.dart b/lib/model/store.dart
index e9974894c6..fda6e5b695 100644
--- a/lib/model/store.dart
+++ b/lib/model/store.dart
@@ -821,11 +821,17 @@ class PerAccountStore extends PerAccountStoreBase with
 
       case ChannelEvent():
         assert(debugLog("server event: stream/${event.op}"));
+        if (event is ChannelDeleteEvent) {
+          _messages.handleChannelDeleteEvent(event);
+        }
         _channels.handleChannelEvent(event);
         notifyListeners();
 
       case SubscriptionEvent():
         assert(debugLog("server event: subscription/${event.op}"));
+        if (event is SubscriptionRemoveEvent) {
+          _messages.handleSubscriptionRemoveEvent(event);
+        }
         _channels.handleSubscriptionEvent(event);
         notifyListeners();
 
diff --git a/test/model/message_test.dart b/test/model/message_test.dart
index 4eccf75112..96d95c0c04 100644
--- a/test/model/message_test.dart
+++ b/test/model/message_test.dart
@@ -36,7 +36,7 @@ void main() {
 
   // These "late" variables are the common state operated on by each test.
   // Each test case calls [prepare] to initialize them.
-  late Subscription subscription;
+  late Subscription? subscription;
   late PerAccountStore store;
   late FakeApiConnection connection;
   // [messageList] is here only for the sake of checking when it notifies.
@@ -54,15 +54,20 @@ void main() {
   /// Initialize [store] and the rest of the test state.
   Future<void> prepare({
     ZulipStream? stream,
+    bool isChannelSubscribed = true,
     int? zulipFeatureLevel,
   }) async {
     stream ??= eg.stream(streamId: eg.defaultStreamMessageStreamId);
-    subscription = eg.subscription(stream);
     final selfAccount = eg.selfAccount.copyWith(zulipFeatureLevel: zulipFeatureLevel);
     store = eg.store(account: selfAccount,
       initialSnapshot: eg.initialSnapshot(zulipFeatureLevel: zulipFeatureLevel));
     await store.addStream(stream);
-    await store.addSubscription(subscription);
+    if (isChannelSubscribed) {
+      subscription = eg.subscription(stream);
+      await store.addSubscription(subscription!);
+    } else {
+      subscription = null;
+    }
     connection = store.connection as FakeApiConnection;
     notifiedCount = 0;
     messageList = MessageListView.init(store: store,
@@ -498,6 +503,9 @@ void main() {
   });
 
   group('reconcileMessages', () {
+    Condition<Object?> conditionIdentical<T>(T element) =>
+      (it) => it.identicalTo(element);
+
     test('from empty', () async {
       await prepare();
       check(store.messages).isEmpty();
@@ -507,8 +515,7 @@ void main() {
       final messages = <Message>[message1, message2, message3];
       store.reconcileMessages(messages);
       check(messages).deepEquals(
-        [message1, message2, message3]
-          .map((m) => (Subject<Object?> it) => it.identicalTo(m)));
+        [message1, message2, message3].map(conditionIdentical));
       check(store.messages).deepEquals({
         for (final m in messages) m.id: m,
       });
@@ -524,24 +531,144 @@ void main() {
       final newMessage = eg.streamMessage();
       store.reconcileMessages([newMessage]);
       check(messages).deepEquals(
-        [message1, message2, message3]
-          .map((m) => (Subject<Object?> it) => it.identicalTo(m)));
+        [message1, message2, message3].map(conditionIdentical));
       check(store.messages).deepEquals({
         for (final m in messages) m.id: m,
         newMessage.id: newMessage,
       });
     });
 
-    test('on ID collision, new message does not clobber old in store.messages', () async {
-      await prepare();
-      final message = eg.streamMessage(id: 1, content: '<p>foo</p>');
-      await addMessages([message]);
-      check(store.messages).deepEquals({1: message});
-      final newMessage = eg.streamMessage(id: 1, content: '<p>bar</p>');
-      final messages = [newMessage];
-      store.reconcileMessages(messages);
-      check(messages).single.identicalTo(message);
-      check(store.messages).deepEquals({1: message});
+    group('fetched message with ID already in store.messages', () {
+      /// Makes a copy of the single message in [MessageStore.messages]
+      /// by round-tripping through [Message.fromJson] and [Message.toJson].
+      ///
+      /// If that message's [StreamMessage.conversation.displayRecipient]
+      /// is null, callers must provide a non-null [displayRecipient]
+      /// to allow [StreamConversation.fromJson] to complete without throwing.
+      Message copyStoredMessage({String? displayRecipient}) {
+        final message = store.messages.values.single;
+
+        final json = message.toJson();
+        if (
+          message is StreamMessage
+          && message.conversation.displayRecipient == null
+        ) {
+          if (displayRecipient == null) throw ArgumentError();
+          json['display_recipient'] = displayRecipient;
+        }
+
+        return Message.fromJson(json);
+      }
+
+      /// Checks if the single message in [MessageStore.messages]
+      /// is identical to [message].
+      void checkStoredMessageIdenticalTo(Message message) {
+        check(store.messages)
+          .deepEquals({message.id: conditionIdentical(message)});
+      }
+
+      void checkClobber({Message? withMessageCopy}) {
+        final messageCopy = withMessageCopy ?? copyStoredMessage();
+        store.reconcileMessages([messageCopy]);
+        checkStoredMessageIdenticalTo(messageCopy);
+      }
+
+      void checkNoClobber() {
+        final messageBefore = store.messages.values.single;
+        store.reconcileMessages([copyStoredMessage()]);
+        checkStoredMessageIdenticalTo(messageBefore);
+      }
+
+      test('DM', () async {
+        await prepare();
+        final message = eg.dmMessage(id: 1, from: eg.otherUser, to: [eg.selfUser]);
+
+        store.reconcileMessages([message]);
+
+        // Not clobbering, because the first call didn't mark stale.
+        checkNoClobber();
+      });
+
+      group('channel message; chooses correctly whether to clobber the stored version', () {
+        // Exercise the ways we move the message in and out of the "maybe stale"
+        // state. These include reconcileMessage itself, so sometimes we test
+        // repeated calls to that with nothing else happening in between.
+
+        test('various conditions', () async {
+          final channel = eg.stream();
+          await prepare(stream: channel, isChannelSubscribed: true);
+          final message = eg.streamMessage(stream: channel);
+
+          store.reconcileMessages([message]);
+
+          // Not clobbering, because the first call didn't mark stale,
+          // because the message was in a subscribed channel.
+          checkNoClobber();
+
+          await store.removeSubscription(channel.streamId);
+          // Clobbering because the unsubscribe event marked the message stale.
+          checkClobber();
+          // (Check that reconcileMessage itself didn't unmark as stale.)
+          checkClobber();
+
+          await store.addSubscription(eg.subscription(channel));
+          // The channel became subscribed,
+          // but the message's data hasn't been refreshed, so clobber…
+          checkClobber();
+
+          // …Now it's been refreshed, by reconcileMessages, so don't clobber.
+          checkNoClobber();
+
+          final otherChannel = eg.stream();
+          await store.addStream(otherChannel);
+          check(store.subscriptions[otherChannel.streamId]).isNull();
+          await store.handleEvent(
+            eg.updateMessageEventMoveFrom(origMessages: [message],
+              newStreamId: otherChannel.streamId));
+          // Message was moved to an unsubscribed channel, so clobber.
+          checkClobber(
+            withMessageCopy: copyStoredMessage(displayRecipient: otherChannel.name));
+          // (Check that reconcileMessage itself didn't unmark as stale.)
+          checkClobber();
+
+          // Subscribe, to mark message as not-stale, setting up another check…
+          await store.addSubscription(eg.subscription(otherChannel));
+
+          await store.handleEvent(ChannelDeleteEvent(id: 1, streams: [otherChannel]));
+          // Message was in a channel that became unknown, so clobber.
+          checkClobber();
+        });
+
+        test('in unsubscribed channel on first call', () async {
+          await prepare(isChannelSubscribed: false);
+          final message = eg.streamMessage();
+
+          store.reconcileMessages([message]);
+
+          checkClobber();
+          checkClobber();
+        });
+
+        test('new-message event when in unsubscribed channel', () async {
+          await prepare(isChannelSubscribed: false);
+          final message = eg.streamMessage();
+
+          await store.handleEvent(eg.messageEvent(message));
+
+          checkClobber();
+          checkClobber();
+        });
+
+        test('new-message event when in a subscribed channel', () async {
+          await prepare(isChannelSubscribed: true);
+          final message = eg.streamMessage();
+
+          await store.handleEvent(eg.messageEvent(message));
+
+          checkNoClobber();
+          checkNoClobber();
+        });
+      });
     });
 
     test('matchContent and matchTopic are removed', () async {
diff --git a/test/widgets/compose_box_test.dart b/test/widgets/compose_box_test.dart
index 15a0a7f81e..ef317277ae 100644
--- a/test/widgets/compose_box_test.dart
+++ b/test/widgets/compose_box_test.dart
@@ -160,7 +160,7 @@ void main() {
       final channel = eg.stream();
       await prepareComposeBox(tester,
         narrow: ChannelNarrow(channel.streamId),
-        streams: [channel],
+        subscriptions: [eg.subscription(channel)],
         messages: [eg.streamMessage(stream: channel)]);
       check(controller).isA<StreamComposeBoxController>()
         ..topicFocusNode.hasFocus.isFalse()
@@ -171,7 +171,7 @@ void main() {
       final channel = eg.stream();
       await prepareComposeBox(tester,
         narrow: ChannelNarrow(channel.streamId),
-        streams: [channel],
+        subscriptions: [eg.subscription(channel)],
         messages: []);
       check(controller).isA<StreamComposeBoxController>()
         .topicFocusNode.hasFocus.isTrue();
@@ -181,7 +181,7 @@ void main() {
       final channel = eg.stream();
       await prepareComposeBox(tester,
         narrow: TopicNarrow(channel.streamId, eg.t('topic')),
-        streams: [channel],
+        subscriptions: [eg.subscription(channel)],
         messages: [eg.streamMessage(stream: channel, topic: 'topic')]);
       check(controller).isNotNull().contentFocusNode.hasFocus.isFalse();
     });
@@ -190,7 +190,7 @@ void main() {
       final channel = eg.stream();
       await prepareComposeBox(tester,
         narrow: TopicNarrow(channel.streamId, eg.t('topic')),
-        streams: [channel],
+        subscriptions: [eg.subscription(channel)],
         messages: []);
       check(controller).isNotNull().contentFocusNode.hasFocus.isTrue();
     });
@@ -379,7 +379,7 @@ void main() {
         addTearDown(MessageStoreImpl.debugReset);
 
         final narrow = ChannelNarrow(channel.streamId);
-        await prepareComposeBox(tester, narrow: narrow, streams: [channel]);
+        await prepareComposeBox(tester, narrow: narrow, subscriptions: [eg.subscription(channel)]);
         await enterTopic(tester, narrow: narrow, topic: 'some topic');
         await enterContent(tester, content);
       }
@@ -418,7 +418,7 @@ void main() {
         addTearDown(MessageStoreImpl.debugReset);
 
         final narrow = ChannelNarrow(channel.streamId);
-        await prepareComposeBox(tester, narrow: narrow, streams: [channel]);
+        await prepareComposeBox(tester, narrow: narrow, subscriptions: [eg.subscription(channel)]);
         await enterTopic(tester, narrow: narrow, topic: topic);
         await enterContent(tester, 'some content');
       }
@@ -462,7 +462,7 @@ void main() {
       await prepareComposeBox(tester,
         narrow: narrow,
         otherUsers: [eg.otherUser, eg.thirdUser],
-        streams: [channel],
+        subscriptions: [eg.subscription(channel)],
         mandatoryTopics: mandatoryTopics,
         zulipFeatureLevel: zulipFeatureLevel);
     }
@@ -736,14 +736,14 @@ void main() {
     testWidgets('_StreamComposeBox', (tester) async {
       final channel = eg.stream();
       await prepareComposeBox(tester,
-        narrow: ChannelNarrow(channel.streamId), streams: [channel]);
+        narrow: ChannelNarrow(channel.streamId), subscriptions: [eg.subscription(channel)]);
       checkComposeBoxTextFields(tester, expectTopicTextField: true);
     });
 
     testWidgets('_FixedDestinationComposeBox', (tester) async {
       final channel = eg.stream();
       await prepareComposeBox(tester,
-        narrow: eg.topicNarrow(channel.streamId, 'topic'), streams: [channel]);
+        narrow: eg.topicNarrow(channel.streamId, 'topic'), subscriptions: [eg.subscription(channel)]);
       checkComposeBoxTextFields(tester, expectTopicTextField: false);
     });
   });
@@ -762,7 +762,8 @@ void main() {
     }
 
     testWidgets('smoke TopicNarrow', (tester) async {
-      await prepareComposeBox(tester, narrow: narrow, streams: [channel]);
+      await prepareComposeBox(tester,
+        narrow: narrow, subscriptions: [eg.subscription(channel)]);
 
       await checkStartTyping(tester, narrow);
 
@@ -786,7 +787,8 @@ void main() {
     testWidgets('smoke ChannelNarrow', (tester) async {
       final narrow = ChannelNarrow(channel.streamId);
       final destinationNarrow = eg.topicNarrow(narrow.streamId, 'test topic');
-      await prepareComposeBox(tester, narrow: narrow, streams: [channel]);
+      await prepareComposeBox(tester,
+        narrow: narrow, subscriptions: [eg.subscription(channel)]);
       await enterTopic(tester, narrow: narrow, topic: 'test topic');
 
       await checkStartTyping(tester, destinationNarrow);
@@ -797,7 +799,8 @@ void main() {
     });
 
     testWidgets('clearing text sends a "typing stopped" notice', (tester) async {
-      await prepareComposeBox(tester, narrow: narrow, streams: [channel]);
+      await prepareComposeBox(tester,
+        narrow: narrow, subscriptions: [eg.subscription(channel)]);
 
       await checkStartTyping(tester, narrow);
 
@@ -809,7 +812,8 @@ void main() {
     testWidgets('hitting send button sends a "typing stopped" notice', (tester) async {
       MessageStoreImpl.debugOutboxEnable = false;
       addTearDown(MessageStoreImpl.debugReset);
-      await prepareComposeBox(tester, narrow: narrow, streams: [channel]);
+      await prepareComposeBox(tester,
+        narrow: narrow, subscriptions: [eg.subscription(channel)]);
 
       await checkStartTyping(tester, narrow);
 
@@ -855,7 +859,8 @@ void main() {
     testWidgets('for content input, unfocusing sends a "typing stopped" notice', (tester) async {
       final narrow = ChannelNarrow(channel.streamId);
       final destinationNarrow = eg.topicNarrow(narrow.streamId, 'test topic');
-      await prepareComposeBox(tester, narrow: narrow, streams: [channel]);
+      await prepareComposeBox(tester,
+        narrow: narrow, subscriptions: [eg.subscription(channel)]);
       await enterTopic(tester, narrow: narrow, topic: 'test topic');
 
       await checkStartTyping(tester, destinationNarrow);
@@ -867,7 +872,8 @@ void main() {
     });
 
     testWidgets('selection change sends a "typing started" notice', (tester) async {
-      await prepareComposeBox(tester, narrow: narrow, streams: [channel]);
+      await prepareComposeBox(tester,
+        narrow: narrow, subscriptions: [eg.subscription(channel)]);
 
       await checkStartTyping(tester, narrow);
 
@@ -887,7 +893,8 @@ void main() {
     });
 
     testWidgets('unfocusing app sends a "typing stopped" notice', (tester) async {
-      await prepareComposeBox(tester, narrow: narrow, streams: [channel]);
+      await prepareComposeBox(tester,
+        narrow: narrow, subscriptions: [eg.subscription(channel)]);
 
       await checkStartTyping(tester, narrow);
 
@@ -919,8 +926,9 @@ void main() {
       addTearDown(MessageStoreImpl.debugReset);
 
       final zulipLocalizations = GlobalLocalizations.zulipLocalizations;
-      await prepareComposeBox(tester, narrow: eg.topicNarrow(123, 'some topic'),
-        streams: [eg.stream(streamId: 123)]);
+      await prepareComposeBox(tester,
+        narrow: eg.topicNarrow(123, 'some topic'),
+        subscriptions: [eg.subscription(eg.stream(streamId: 123))]);
 
       await enterContent(tester, 'hello world');
 
@@ -977,7 +985,7 @@ void main() {
       channel = eg.stream();
       final narrow = ChannelNarrow(channel.streamId);
       await prepareComposeBox(tester,
-        narrow: narrow, streams: [channel],
+        narrow: narrow, subscriptions: [eg.subscription(channel)],
         mandatoryTopics: mandatoryTopics,
         zulipFeatureLevel: zulipFeatureLevel);
 
@@ -1057,7 +1065,8 @@ void main() {
 
       final channel = eg.stream();
       final narrow = ChannelNarrow(channel.streamId);
-      await prepareComposeBox(tester, narrow: narrow, streams: [channel]);
+      await prepareComposeBox(tester,
+        narrow: narrow, subscriptions: [eg.subscription(channel)]);
 
       // (When we check that the send button looks disabled, it should be because
       // the file is uploading, not a pre-existing reason.)
@@ -1175,7 +1184,8 @@ void main() {
 
       final channel = eg.stream();
       final narrow = eg.topicNarrow(channel.streamId, 'a topic');
-      await prepareComposeBox(tester, narrow: narrow, streams: [channel]);
+      await prepareComposeBox(tester,
+        narrow: narrow, subscriptions: [eg.subscription(channel)]);
 
       testBinding.pickFilesResult = FilePickerResult([PlatformFile(
         readStream: Stream.fromIterable(['asdf'.codeUnits]),
@@ -1631,7 +1641,8 @@ void main() {
     }
 
     testWidgets('normal text scale factor', (tester) async {
-      await prepareComposeBox(tester, narrow: narrow, streams: [stream]);
+      await prepareComposeBox(tester,
+        narrow: narrow, subscriptions: [eg.subscription(stream)]);
 
       await checkContentInputMaxHeight(tester,
         maxHeight: verticalPadding + 170, maxVisibleLines: 8);
@@ -1640,7 +1651,8 @@ void main() {
     testWidgets('lower text scale factor', (tester) async {
       tester.platformDispatcher.textScaleFactorTestValue = 0.8;
       addTearDown(tester.platformDispatcher.clearTextScaleFactorTestValue);
-      await prepareComposeBox(tester, narrow: narrow, streams: [stream]);
+      await prepareComposeBox(tester,
+        narrow: narrow, subscriptions: [eg.subscription(stream)]);
       await checkContentInputMaxHeight(tester,
         maxHeight: verticalPadding + 170 * 0.8, maxVisibleLines: 8);
     });
@@ -1648,7 +1660,8 @@ void main() {
     testWidgets('higher text scale factor', (tester) async {
       tester.platformDispatcher.textScaleFactorTestValue = 1.5;
       addTearDown(tester.platformDispatcher.clearTextScaleFactorTestValue);
-      await prepareComposeBox(tester, narrow: narrow, streams: [stream]);
+      await prepareComposeBox(tester,
+        narrow: narrow, subscriptions: [eg.subscription(stream)]);
       await checkContentInputMaxHeight(tester,
         maxHeight: verticalPadding + 170 * 1.5, maxVisibleLines: 8);
     });
@@ -1656,7 +1669,8 @@ void main() {
     testWidgets('higher text scale factor exceeding threshold', (tester) async {
       tester.platformDispatcher.textScaleFactorTestValue = 2;
       addTearDown(tester.platformDispatcher.clearTextScaleFactorTestValue);
-      await prepareComposeBox(tester, narrow: narrow, streams: [stream]);
+      await prepareComposeBox(tester,
+        narrow: narrow, subscriptions: [eg.subscription(stream)]);
       await checkContentInputMaxHeight(tester,
         maxHeight: verticalPadding + 170 * 1.5, maxVisibleLines: 6);
     });
@@ -1671,7 +1685,8 @@ void main() {
 
       final channel = eg.stream();
       await prepareComposeBox(tester,
-        narrow: eg.topicNarrow(channel.streamId, 'topic'), streams: [channel]);
+        narrow: eg.topicNarrow(channel.streamId, 'topic'),
+        subscriptions: [eg.subscription(channel)]);
 
       await enterContent(tester, 'some content');
       checkContentInputValue(tester, 'some content');
@@ -1769,7 +1784,9 @@ void main() {
       TypingNotifier.debugEnable = false;
       addTearDown(TypingNotifier.debugReset);
       await prepareComposeBox(tester,
-        narrow: narrow, streams: [channel], otherUsers: otherUsers);
+        narrow: narrow,
+        subscriptions: [eg.subscription(channel)],
+        otherUsers: otherUsers);
 
       if (narrow is ChannelNarrow) {
         connection.prepare(json: GetStreamTopicsResult(topics: []).toJson());
@@ -1937,7 +1954,7 @@ void main() {
       addTearDown(MessageStoreImpl.debugReset);
       await prepareComposeBox(tester,
         narrow: narrow,
-        streams: [channel]);
+        subscriptions: [eg.subscription(channel)]);
       await store.addMessages([message, dmMessage]);
       await tester.pump(); // message list updates
     }
diff --git a/test/widgets/message_list_test.dart b/test/widgets/message_list_test.dart
index acdde3fd2c..240285a222 100644
--- a/test/widgets/message_list_test.dart
+++ b/test/widgets/message_list_test.dart
@@ -154,7 +154,7 @@ void main() {
     testWidgets('MessageListPageState.narrow', (tester) async {
       final stream = eg.stream();
       await setupMessageListPage(tester, narrow: ChannelNarrow(stream.streamId),
-        streams: [stream],
+        subscriptions: [eg.subscription(stream)],
         messages: [eg.streamMessage(stream: stream, content: "<p>a message</p>")]);
       final state = MessageListPage.ancestorOf(tester.element(find.text("a message")));
       check(state.narrow).equals(ChannelNarrow(stream.streamId));
@@ -167,7 +167,7 @@ void main() {
       final topic = eg.defaultRealmEmptyTopicDisplayName;
       final topicNarrow = eg.topicNarrow(stream.streamId, topic);
       await setupMessageListPage(tester, narrow: topicNarrow,
-        streams: [stream],
+        subscriptions: [eg.subscription(stream)],
         messages: [eg.streamMessage(stream: stream, topic: topic, content: "<p>a message</p>")]);
       final state = MessageListPage.ancestorOf(tester.element(find.text("a message")));
       // The page's narrow has been updated; the topic is "", not "general chat".
@@ -177,7 +177,7 @@ void main() {
     testWidgets('composeBoxState finds compose box', (tester) async {
       final stream = eg.stream();
       await setupMessageListPage(tester, narrow: ChannelNarrow(stream.streamId),
-        streams: [stream],
+        subscriptions: [eg.subscription(stream)],
         messages: [eg.streamMessage(stream: stream, content: "<p>a message</p>")]);
       final state = MessageListPage.ancestorOf(tester.element(find.text("a message")));
       check(state.composeBoxState).isNotNull();
@@ -238,7 +238,7 @@ void main() {
       final channel = eg.stream();
       await setupMessageListPage(tester,
         narrow: eg.topicNarrow(channel.streamId, ''),
-        streams: [channel],
+        subscriptions: [eg.subscription(channel)],
         messageCount: 1);
       checkAppBarChannelTopic(
         channel.name, eg.defaultRealmEmptyTopicDisplayName);
@@ -281,7 +281,7 @@ void main() {
       final channel = eg.stream();
       await setupMessageListPage(tester, narrow: eg.topicNarrow(channel.streamId, 'hi'),
         navObservers: [navObserver],
-        streams: [channel], messageCount: 1);
+        subscriptions: [eg.subscription(channel)], messageCount: 1);
 
       // Clear out initial route.
       assert(pushedRoutes.length == 1);
@@ -298,7 +298,7 @@ void main() {
       final channel = eg.stream(name: 'channel foo');
       await setupMessageListPage(tester,
         narrow: eg.topicNarrow(channel.streamId, 'topic foo'),
-        streams: [channel],
+        subscriptions: [eg.subscription(channel)],
         messages: [eg.streamMessage(stream: channel, topic: 'topic foo')]);
 
       connection.prepare(json: GetStreamTopicsResult(topics: [
@@ -333,7 +333,7 @@ void main() {
       final channel = eg.stream(name: 'channel foo');
       await setupMessageListPage(tester,
         narrow: ChannelNarrow(channel.streamId),
-        streams: [channel],
+        subscriptions: [eg.subscription(channel)],
         messages: [eg.streamMessage(stream: channel, topic: 'topic foo')]);
 
       connection.prepare(json: GetStreamTopicsResult(topics: [
@@ -390,7 +390,7 @@ void main() {
       final channel = eg.stream();
       await setupMessageListPage(tester,
         narrow: TopicNarrow(channel.streamId, eg.t('topic')),
-        streams: [channel],
+        subscriptions: [eg.subscription(channel)],
         messages: []);
       check(findPlaceholder).findsOne();
 
@@ -488,9 +488,11 @@ void main() {
 
     group('topic permalink', () {
       final someStream = eg.stream();
+      final someSubscription = eg.subscription(someStream);
       const someTopic = 'some topic';
 
       final otherStream = eg.stream();
+      final otherSubscription = eg.subscription(otherStream);
       const otherTopic = 'other topic';
 
       testWidgets('with message move', (tester) async {
@@ -499,7 +501,7 @@ void main() {
           narrow: narrow,
           // server sends the /with/<id> message in its current, different location
           messages: [eg.streamMessage(id: 1, stream: otherStream, topic: otherTopic)],
-          streams: [someStream, otherStream],
+          subscriptions: [someSubscription, otherSubscription],
           skipPumpAndSettle: true);
         await tester.pump(); // global store loaded
         await tester.pump(); // per-account store loaded
@@ -533,7 +535,7 @@ void main() {
           narrow: narrow,
           // server sends the /with/<id> message in its current, different location
           messages: [eg.streamMessage(id: 1, stream: someStream, topic: someTopic)],
-          streams: [someStream],
+          subscriptions: [someSubscription],
           skipPumpAndSettle: true);
         await tester.pump(); // global store loaded
         await tester.pump(); // per-account store loaded
@@ -1182,7 +1184,9 @@ void main() {
   group('Update Narrow on message move', () {
     const topic = 'foo';
     final channel = eg.stream();
+    final subscription = eg.subscription(channel);
     final otherChannel = eg.stream();
+    final otherSubscription = eg.subscription(otherChannel);
     final narrow = eg.topicNarrow(channel.streamId, topic);
 
     void prepareGetMessageResponse(List<Message> messages) {
@@ -1200,7 +1204,10 @@ void main() {
 
     testWidgets('compose box send message after move', (tester) async {
       final message = eg.streamMessage(stream: channel, topic: topic, content: 'Message to move');
-      await setupMessageListPage(tester, narrow: narrow, messages: [message], streams: [channel, otherChannel]);
+      await setupMessageListPage(tester,
+        narrow: narrow,
+        messages: [message],
+        subscriptions: [subscription, otherSubscription]);
 
       final channelContentInputFinder = find.descendant(
         of: find.byType(ComposeAutocomplete),
@@ -1240,7 +1247,8 @@ void main() {
 
     testWidgets('Move to narrow with existing messages', (tester) async {
       final message = eg.streamMessage(stream: channel, topic: topic, content: 'Message to move');
-      await setupMessageListPage(tester, narrow: narrow, messages: [message], streams: [channel]);
+      await setupMessageListPage(tester,
+        narrow: narrow, messages: [message], subscriptions: [subscription]);
       check(find.textContaining('Existing message').evaluate()).length.equals(0);
       check(find.textContaining('Message to move').evaluate()).length.equals(1);
 
@@ -1256,7 +1264,8 @@ void main() {
 
     testWidgets('show new topic in TopicNarrow after move', (tester) async {
       final message = eg.streamMessage(stream: channel, topic: topic, content: 'Message to move');
-      await setupMessageListPage(tester, narrow: narrow, messages: [message], streams: [channel]);
+      await setupMessageListPage(tester,
+        narrow: narrow, messages: [message], subscriptions: [subscription]);
 
       prepareGetMessageResponse([message]);
       await handleMessageMoveEvent([message], 'new topic');
@@ -1315,7 +1324,7 @@ void main() {
       testWidgets('do not show channel name in ChannelNarrow', (tester) async {
         await setupMessageListPage(tester,
           narrow: ChannelNarrow(stream.streamId),
-          messages: [message], streams: [stream]);
+          messages: [message], subscriptions: [eg.subscription(stream)]);
         await tester.pump();
         check(findInMessageList('stream name')).length.equals(0);
         check(findInMessageList('topic name')).length.equals(1);
@@ -1324,7 +1333,7 @@ void main() {
       testWidgets('do not show stream name in TopicNarrow', (tester) async {
         await setupMessageListPage(tester,
           narrow: TopicNarrow.ofMessage(message),
-          messages: [message], streams: [stream]);
+          messages: [message], subscriptions: [eg.subscription(stream)]);
         await tester.pump();
         check(findInMessageList('stream name')).length.equals(0);
         check(findInMessageList('topic name')).length.equals(1);
@@ -1505,7 +1514,7 @@ void main() {
         final message = eg.streamMessage(stream: channel, topic: 'topic name');
         await setupMessageListPage(tester,
           narrow: ChannelNarrow(channel.streamId),
-          streams: [channel],
+          subscriptions: [eg.subscription(channel)],
           messages: [message],
           navObservers: [navObserver]);
 
@@ -1531,7 +1540,7 @@ void main() {
         final message = eg.streamMessage(stream: channel, topic: 'topic name');
         await setupMessageListPage(tester,
           narrow: TopicNarrow.ofMessage(message),
-          streams: [channel],
+          subscriptions: [eg.subscription(channel)],
           messages: [message],
           navObservers: [navObserver]);
 
@@ -2136,7 +2145,7 @@ void main() {
 
     testWidgets('hidden -> waiting', (tester) async {
       await setupMessageListPage(tester,
-        narrow: topicNarrow, streams: [stream],
+        narrow: topicNarrow, subscriptions: [eg.subscription(stream)],
         messages: []);
 
       await sendMessageAndSucceed(tester);
@@ -2152,7 +2161,7 @@ void main() {
 
     testWidgets('hidden -> failed, tap to restore message', (tester) async {
       await setupMessageListPage(tester,
-        narrow: topicNarrow, streams: [stream],
+        narrow: topicNarrow, subscriptions: [eg.subscription(stream)],
         messages: []);
       // Send a message and fail.  Dismiss the error dialog as it pops up.
       await sendMessageAndFail(tester);
@@ -2200,7 +2209,7 @@ void main() {
 
     testWidgets('waiting -> waitPeriodExpired, tap to restore message', (tester) async {
       await setupMessageListPage(tester,
-        narrow: topicNarrow, streams: [stream],
+        narrow: topicNarrow, subscriptions: [eg.subscription(stream)],
         messages: []);
       await sendMessageAndFail(tester,
         delay: kSendMessageOfferRestoreWaitPeriod + const Duration(seconds: 1));