diff --git a/lib/widgets/inbox.dart b/lib/widgets/inbox.dart
index 69421fa50e..00c17841af 100644
--- a/lib/widgets/inbox.dart
+++ b/lib/widgets/inbox.dart
@@ -134,12 +134,14 @@ class _InboxPageState extends State<InboxPage> with PerAccountStoreAwareStateMix
     for (final MapEntry(key: streamId, value: topics) in sortedUnreadStreams) {
       final topicItems = <(String, int, bool, int)>[];
       int countInStream = 0;
+      bool mentionedInStream = false;
       for (final MapEntry(key: topic, value: messageIds) in topics.entries) {
         if (!store.isTopicVisible(streamId, topic)) continue;
         final countInTopic = messageIds.length;
         final isMentioned = messageIds.any((messageId) => unreadsModel!.mentions.contains(messageId));
         topicItems.add((topic, countInTopic, isMentioned, messageIds.last));
         countInStream += countInTopic;
+        if (isMentioned) mentionedInStream = true;
       }
       if (countInStream == 0) {
         continue;
@@ -149,7 +151,7 @@ class _InboxPageState extends State<InboxPage> with PerAccountStoreAwareStateMix
         final (_, _, _, bLastUnreadId) = b;
         return bLastUnreadId.compareTo(aLastUnreadId);
       });
-      sections.add(_StreamSectionData(streamId, countInStream, topicItems));
+      sections.add(_StreamSectionData(streamId, countInStream, mentionedInStream, topicItems));
     }
 
     return Scaffold(
@@ -190,20 +192,23 @@ class _AllDmsSectionData extends _InboxSectionData {
 class _StreamSectionData extends _InboxSectionData {
   final int streamId;
   final int count;
+  final bool isMentioned;
   final List<(String, int, bool, int)> items;
 
-  const _StreamSectionData(this.streamId, this.count, this.items);
+  const _StreamSectionData(this.streamId, this.count, this.isMentioned, this.items);
 }
 
 abstract class _HeaderItem extends StatelessWidget {
   final bool collapsed;
   final _InboxPageState pageState;
   final int count;
+  final bool isMentioned;
 
   const _HeaderItem({
     required this.collapsed,
     required this.pageState,
     required this.count,
+    required this.isMentioned,
   });
 
   String get title;
@@ -247,7 +252,7 @@ abstract class _HeaderItem extends StatelessWidget {
               overflow: TextOverflow.ellipsis,
               title))),
           const SizedBox(width: 12),
-          // TODO(#384) for streams, show @-mention indicator when it applies
+          if (isMentioned) const _AtMentionMarker(),
           Padding(padding: const EdgeInsetsDirectional.only(end: 16),
             child: UnreadCountBadge(backgroundColor: unreadCountBadgeBackgroundColor, bold: true,
               count: count)),
@@ -260,6 +265,7 @@ class _AllDmsHeaderItem extends _HeaderItem {
     required super.collapsed,
     required super.pageState,
     required super.count,
+    required super.isMentioned,
   });
 
   @override get title => 'Direct messages'; // TODO(i18n)
@@ -290,6 +296,7 @@ class _AllDmsSection extends StatelessWidget {
   Widget build(BuildContext context) {
     final header = _AllDmsHeaderItem(
       count: data.count,
+      isMentioned: false,
       collapsed: collapsed,
       pageState: pageState,
     );
@@ -341,6 +348,7 @@ class _DmItem extends StatelessWidget {
     return StickyHeaderItem(
       header: _AllDmsHeaderItem(
         count: allDmsCount,
+        isMentioned: false,
         collapsed: false,
         pageState: pageState,
       ),
@@ -382,6 +390,7 @@ class _StreamHeaderItem extends _HeaderItem {
     required super.collapsed,
     required super.pageState,
     required super.count,
+    required super.isMentioned,
   });
 
   @override get title => subscription.name;
@@ -420,6 +429,7 @@ class _StreamSection extends StatelessWidget {
     final header = _StreamHeaderItem(
       subscription: subscription,
       count: data.count,
+      isMentioned: data.isMentioned,
       collapsed: collapsed,
       pageState: pageState,
     );
@@ -435,6 +445,7 @@ class _StreamSection extends StatelessWidget {
             count: count,
             isMentioned: isMentioned,
             streamCount: data.count,
+            streamIsMentioned: data.isMentioned,
             pageState: pageState,
           );
         }),
@@ -449,6 +460,7 @@ class _TopicItem extends StatelessWidget {
     required this.count,
     required this.isMentioned,
     required this.streamCount,
+    required this.streamIsMentioned,
     required this.pageState,
   });
 
@@ -457,6 +469,7 @@ class _TopicItem extends StatelessWidget {
   final int count;
   final bool isMentioned;
   final int streamCount;
+  final bool streamIsMentioned;
   final _InboxPageState pageState;
 
   @override
@@ -468,6 +481,7 @@ class _TopicItem extends StatelessWidget {
       header: _StreamHeaderItem(
         subscription: subscription,
         count: streamCount,
+        isMentioned: streamIsMentioned,
         collapsed: false,
         pageState: pageState,
       ),
diff --git a/test/widgets/inbox_test.dart b/test/widgets/inbox_test.dart
index 03db3b8b96..e908709a71 100644
--- a/test/widgets/inbox_test.dart
+++ b/test/widgets/inbox_test.dart
@@ -203,6 +203,8 @@ void main() {
           unreadMessages: [eg.streamMessage(stream: stream, topic: topic,
             flags: [MessageFlag.mentioned])]);
 
+        check(hasAtSign(tester, findStreamHeaderRow(tester, stream.streamId)))
+          .isTrue();
         check(hasAtSign(tester, findRowByLabel(tester, topic))).isTrue();
       });
 
@@ -213,6 +215,8 @@ void main() {
           unreadMessages: [eg.streamMessage(stream: stream, topic: topic,
             flags: [])]);
 
+        check(hasAtSign(tester, findStreamHeaderRow(tester, stream.streamId)))
+          .isFalse();
         check(hasAtSign(tester, findRowByLabel(tester, topic))).isFalse();
       });
     });