diff --git a/frontend/lib/home/notifications_list.dart b/frontend/lib/home/notifications_list.dart
index f8b0541..931f32b 100644
--- a/frontend/lib/home/notifications_list.dart
+++ b/frontend/lib/home/notifications_list.dart
@@ -309,6 +309,7 @@ class _NotificationsListState extends State<NotificationsList>
       itemBuilder: (context, index) {
         final item = _items[index];
         return NotificationCard(
+          key: ValueKey(item.id),
           item: item,
           formatter: formatter,
           onSetRead: (read) => _setRead(item, read),
diff --git a/frontend/test/widget/notifications_list_test.dart b/frontend/test/widget/notifications_list_test.dart
new file mode 100644
index 0000000..09e9709
--- /dev/null
+++ b/frontend/test/widget/notifications_list_test.dart
@@ -0,0 +1,57 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:frontend/home/notifications_list.dart';
+import 'package:frontend/theme/gruvbox_theme.dart';
+import 'package:http_mock_adapter/http_mock_adapter.dart';
+
+import '../helpers/backend_test_harness.dart';
+import '../helpers/fixtures.dart';
+
+void main() {
+  late DioAdapter adapter;
+
+  setUp(() async {
+    adapter = await setUpBackendForTest();
+  });
+
+  testWidgets(
+    'marking an expanded "New" notification as read does not expand the next',
+    (tester) async {
+      adapter.onGet(
+        '/notifications',
+        (server) => server.reply(200, [
+          notificationJson(id: 1, title: 'First', body: 'First body'),
+          notificationJson(id: 2, title: 'Second', body: 'Second body'),
+        ]),
+        queryParameters: {'is_new': true, 'page_offset': 0, 'page_limit': 6},
+      );
+      adapter.onGet('/notifications/1', (server) => server.reply(200, null));
+
+      await tester.pumpWidget(
+        MaterialApp(
+          theme: gruvboxDarkTheme,
+          home: const Scaffold(body: NotificationsList()),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      // Expand the first notification.
+      await tester.tap(find.byType(ListTile).first);
+      await tester.pumpAndSettle();
+      expect(find.text('Mark as read'), findsOneWidget);
+
+      // Mark it as read; it disappears from the "New"-filtered list.
+      await tester.tap(find.text('Mark as read'));
+      await tester.pumpAndSettle();
+
+      // The first notification is gone and the second stays collapsed: no
+      // card is expanded, so no action buttons are showing.
+      expect(find.textContaining('First'), findsNothing);
+      expect(find.textContaining('Second'), findsWidgets);
+      expect(find.text('Mark as read'), findsNothing);
+
+      // Dispose the widget so its polling timer is cancelled.
+      await tester.pumpWidget(const SizedBox());
+    },
+  );
+}