diff --git a/lib/tasks/promotion_code.rake b/lib/tasks/promotion_code.rake
index 13631c2..170d2eb 100644
--- a/lib/tasks/promotion_code.rake
+++ b/lib/tasks/promotion_code.rake
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 namespace :promotion_code do
   task generate: :environment do
-    10.times do |n|
+    10.times do
       code = SecureRandom.alphanumeric(7)
       discount = rand(1..10) * 100
-      PromotionCode.create(code: ,discount:)
+      PromotionCode.create(code:, discount:)
       puts "コード #{code} で#{discount}円割引"
     end
   end