diff --git a/actionmailer/test/mail_service_test.rb b/actionmailer/test/mail_service_test.rb
index 0755f51045..901b03c05f 100755
--- a/actionmailer/test/mail_service_test.rb
+++ b/actionmailer/test/mail_service_test.rb
@@ -1,3 +1,4 @@
+# encoding: utf-8
 require 'abstract_unit'
 
 class FunkyPathMailer < ActionMailer::Base