diff --git a/boards/views/api.py b/boards/views/api.py
--- a/boards/views/api.py
+++ b/boards/views/api.py
@@ -213,7 +213,7 @@ def api_get_notifications(request, usern
     last_notification_id_str = request.GET.get('last', None)
     last_id = int(last_notification_id_str) if last_notification_id_str is not None else None
 
-    posts = Notification.objects.get_notification_posts(usernames=username,
+    posts = Notification.objects.get_notification_posts(usernames=[username],
                                                         last=last_id)
 
     json_post_list = []