diff --git a/actionmailer/lib/action_mailer/helpers.rb b/actionmailer/lib/action_mailer/helpers.rb
index 1bb8682315..ecd8f0f5b6 100644
--- a/actionmailer/lib/action_mailer/helpers.rb
+++ b/actionmailer/lib/action_mailer/helpers.rb
@@ -106,7 +106,7 @@ module ActionMailer
     private
       # Extend the template class instance with our controller's helper module.
       def initialize_template_class_with_helper(assigns)
-        returning(template = initialize_template_class_without_helper(assigns)) do
+        initialize_template_class_without_helper(assigns).tap do |template|
           template.extend self.class.master_helper_module
         end
       end