diff --git a/lib/devise/orm.rb b/lib/devise/orm.rb
index 4c3cd6f4..3f3ac86d 100644
--- a/lib/devise/orm.rb
+++ b/lib/devise/orm.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Devise
   module Orm # :nodoc:
     def self.active_record?(model)