diff --git a/actionmailer/lib/action_mailer/base.rb b/actionmailer/lib/action_mailer/base.rb
index 8f2c567e3e..71c156f1a2 100644
--- a/actionmailer/lib/action_mailer/base.rb
+++ b/actionmailer/lib/action_mailer/base.rb
@@ -668,7 +668,7 @@ module ActionMailer #:nodoc:
       end
     end
 
-    # Translates the +subject+ using Rails I18n class under <tt>[:actionmailer, mailer_scope, action_name]</tt> scope.
+    # Translates the +subject+ using Rails I18n class under <tt>[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 #:nodoc: