diff --git a/db/migrate/20190708062910_add_index_for_run_code_message.rb b/db/migrate/20190708062910_add_index_for_run_code_message.rb
new file mode 100644
index 000000000..4449d58a2
--- /dev/null
+++ b/db/migrate/20190708062910_add_index_for_run_code_message.rb
@@ -0,0 +1,5 @@
+class AddIndexForRunCodeMessage < ActiveRecord::Migration[5.2]
+  def change
+    add_index :run_code_messages, :game_id
+  end
+end