diff --git a/lib/devise/rails.rb b/lib/devise/rails.rb
index dad9e86dc..b5738853f 100644
--- a/lib/devise/rails.rb
+++ b/lib/devise/rails.rb
@@ -47,5 +47,11 @@ class Engine < ::Rails::Engine
           )
         end
     end
+
+    initializer "devise.configure_zeitwerk" do
+      if Rails.autoloaders.zeitwerk_enabled? && !defined?(ActionMailer)
+        Rails.autoloaders.main.ignore("#{root}/app/mailers/devise/mailer.rb")
+      end
+    end
   end
 end