diff --git a/app/controllers/homework_commons_controller.rb b/app/controllers/homework_commons_controller.rb
index 84ee9daf2..cfc1c4ba5 100644
--- a/app/controllers/homework_commons_controller.rb
+++ b/app/controllers/homework_commons_controller.rb
@@ -1597,7 +1597,7 @@ class HomeworkCommonsController < ApplicationController
       att = attachment.copy
       att.author_id = homework_bank.user_id
       att.copy_from = attachment.id
-      att.attachtype = attachment.attachtype
+      att.attachtype = attachment.attachtype || 1
       homework_bank.attachments << att
     end
     homework_bank
diff --git a/app/controllers/question_banks_controller.rb b/app/controllers/question_banks_controller.rb
index 5ff247729..098c07d1b 100644
--- a/app/controllers/question_banks_controller.rb
+++ b/app/controllers/question_banks_controller.rb
@@ -154,7 +154,7 @@ class QuestionBanksController < ApplicationController
           att.container_id = nil
           att.container_type = nil
           att.author_id = homework.user_id
-          att.attachtype = attachment.attachtype
+          att.attachtype = attachment.attachtype || 1
           # att.attachtype = 1
           att.copy_from = attachment.id
           att.save!