diff --git a/zerver/lib/message.py b/zerver/lib/message.py
index 6935fbc11d..ee1290f183 100644
--- a/zerver/lib/message.py
+++ b/zerver/lib/message.py
@@ -518,6 +518,10 @@ def apply_unread_message_event(state, message):
             unread_message_ids=[message_id],
         )
 
+    if message.get('is_mentioned'):
+        if message_id not in state['mentions']:
+            state['mentions'].append(message_id)
+
     for obj in state[unread_key]:
         if key_func(obj) == my_key:
             obj['unread_message_ids'].append(message_id)
@@ -526,6 +530,3 @@ def apply_unread_message_event(state, message):
 
     state[unread_key].append(new_obj)
     state[unread_key].sort(key=key_func)
-
-    if message.get('is_mentioned'):
-        state['mentions'].append(message_id)
diff --git a/zerver/tests/test_events.py b/zerver/tests/test_events.py
index 7b1034c39c..69f1cce6f7 100644
--- a/zerver/tests/test_events.py
+++ b/zerver/tests/test_events.py
@@ -452,14 +452,16 @@ class EventsRegisterTest(ZulipTestCase):
     def test_mentioned_send_message_events(self):
         # type: () -> None
         user = self.example_user('hamlet')
-        content = 'mentioning... @**' + user.full_name + '**'
-        self.do_test(
-            lambda: self.send_message(self.example_email('cordelia'),
-                                      "Verona",
-                                      Recipient.STREAM,
-                                      content)
 
-        )
+        for i in range(3):
+            content = 'mentioning... @**' + user.full_name + '** hello ' + str(i)
+            self.do_test(
+                lambda: self.send_message(self.example_email('cordelia'),
+                                          "Verona",
+                                          Recipient.STREAM,
+                                          content)
+
+            )
 
     def test_pm_send_message_events(self):
         # type: () -> None