diff --git a/app/services/post_alerter.rb b/app/services/post_alerter.rb
index aad37984b..d81728f9a 100644
--- a/app/services/post_alerter.rb
+++ b/app/services/post_alerter.rb
@@ -153,7 +153,7 @@ class PostAlerter
         inbox_count: Topic.exec_sql(
         "SELECT COUNT(*) FROM topics t
          JOIN topic_allowed_groups g ON g.group_id = :group_id AND g.topic_id = t.id
-         LEFT JOIN group_archived_messages a ON a.topic_id = t.id AND a.group_id = g.id
+         LEFT JOIN group_archived_messages a ON a.topic_id = t.id AND a.group_id = g.group_id
          WHERE a.id IS NULL AND t.deleted_at is NULL AND t.archetype = 'private_message'",
           group_id: g.id).values[0][0].to_i
       }