diff --git a/push_notifications.py b/home/zulip/deployments/current/zerver/lib/push_notifications.py
index 7023639..9c08d8f 100644
--- a/push_notifications.py
+++ b/home/zulip/deployments/current/zerver/lib/push_notifications.py
@@ -1042,10 +1042,14 @@ def get_apns_alert_subtitle(
 def get_apns_badge_count(
     user_profile: UserProfile, read_messages_ids: Optional[Sequence[int]] = []
 ) -> int:
-    # NOTE: We have temporarily set get_apns_badge_count to always
-    # return 0 until we can debug a likely mobile app side issue with
-    # handling notifications while the app is open.
-    return 0
+    # The iOS mobile app does not keep a correct badge count after the app is opened,
+    # but will show the correct value when the push notfication is received. Issue
+    # number https://github.com/zulip/zulip-mobile/issues/438
+    return (
+        UserMessage.objects.filter(user_profile=user_profile)
+        .extra(where=[UserMessage.where_unread()])
+        .count()
+    )


 def get_apns_badge_count_future(