diff --git a/dictation_server/db/migrations/051-delete-license-alert.sql b/dictation_server/db/migrations/051-delete-license-alert.sql
new file mode 100644
index 0000000..e191a81
--- /dev/null
+++ b/dictation_server/db/migrations/051-delete-license-alert.sql
@@ -0,0 +1,6 @@
+-- +migrate Up
+ALTER TABLE `users` DROP COLUMN `license_alert`;
+
+
+-- +migrate Down
+ALTER TABLE `users` ADD COLUMN `license_alert` BOOLEAN DEFAULT TRUE NOT NULL COMMENT 'ライセンスの期限切れ通知をするかどうか';
\ No newline at end of file