diff --git a/db/migrate/20200111024736_add_index_for_subject_records.rb b/db/migrate/20200111024736_add_index_for_subject_records.rb
index c27c9b9ae..e196c407f 100644
--- a/db/migrate/20200111024736_add_index_for_subject_records.rb
+++ b/db/migrate/20200111024736_add_index_for_subject_records.rb
@@ -1,6 +1,6 @@
 class AddIndexForSubjectRecords < ActiveRecord::Migration[5.2]
   def change
-    remove_index :subject_records, :subject_id
+    # remove_index :subject_records, :subject_id
     add_index :subject_records, :subject_id, unique: true
   end
 end