diff --git a/actionmailer/lib/action_mailer/base.rb b/actionmailer/lib/action_mailer/base.rb
index bf7e50596a6f2d15bf1bab7958c0dfb23f0e0c7d..06de43b76f4918f00b1ca518d470759bffbc0de1 100644
--- a/actionmailer/lib/action_mailer/base.rb
+++ b/actionmailer/lib/action_mailer/base.rb
@@ -688,7 +688,7 @@ def set_content_type(m, user_content_type, class_default)
     # Translates the +subject+ using Rails I18n class under <tt>[:actionmailer, mailer_scope, action_name]</tt> scope.
     # If it does not find a translation for the +subject+ under the specified scope it will default to a
     # humanized version of the <tt>action_name</tt>.
-    def default_i18n_subject
+    def default_i18n_subject #:nodoc:
       mailer_scope = self.class.mailer_name.gsub('/', '.')
       I18n.t(:subject, :scope => [mailer_scope, action_name], :default => action_name.humanize)
     end