diff --git a/activestorage/app/controllers/active_storage/representations/base_controller.rb b/activestorage/app/controllers/active_storage/representations/base_controller.rb
index 52c49b0881..3b4cc9ca2d 100644
--- a/activestorage/app/controllers/active_storage/representations/base_controller.rb
+++ b/activestorage/app/controllers/active_storage/representations/base_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ActiveStorage::Representations::BaseController < ActiveStorage::BaseController #:nodoc:
   include ActiveStorage::SetBlob