diff --git a/db/migrate/20150918063404_normal_homework_type.rb b/db/migrate/20150918063404_normal_homework_type.rb
index def3b0024..0d70d94be 100644
--- a/db/migrate/20150918063404_normal_homework_type.rb
+++ b/db/migrate/20150918063404_normal_homework_type.rb
@@ -4,5 +4,6 @@ class NormalHomeworkType < ActiveRecord::Migration
   end
 
   def down
+    HomeworkCommon.where("homework_type = 0").update_all(:homework_type => 1)
   end
 end