diff --git a/db/migrate/20190725024516_modify_attachment_url_for_challenge_answer.rb b/db/migrate/20190725024516_modify_attachment_url_for_challenge_answer.rb
new file mode 100644
index 000000000..41840bac1
--- /dev/null
+++ b/db/migrate/20190725024516_modify_attachment_url_for_challenge_answer.rb
@@ -0,0 +1,7 @@
+class ModifyAttachmentUrlForChallengeAnswer < ActiveRecord::Migration[5.2]
+  def change
+    ChallengeChoose.find_each do |cc|
+      cc.update_column(:subject, cc.subject.gsub("(/attachments/download", "(/api/attachments")) if cc.subject.present?
+    end
+  end
+end