diff --git a/app/controllers/graduation_tasks_controller.rb b/app/controllers/graduation_tasks_controller.rb
index 5e48e0139..117989247 100644
--- a/app/controllers/graduation_tasks_controller.rb
+++ b/app/controllers/graduation_tasks_controller.rb
@@ -225,7 +225,7 @@ class GraduationTasksController < ApplicationController
       }
       attachment = work.attachments.last
       if attachment
-        o[:downloadUrl] = "https://#{Setting.host_name}/"+download_url(attachment)
+        o[:downloadUrl] = "https://#{edu_setting('host_name')}/"+download_url(attachment)
       end
 
       o