diff --git a/app/models/mailer.rb b/app/models/mailer.rb
index 7a6061835..919e5bb00 100644
--- a/app/models/mailer.rb
+++ b/app/models/mailer.rb
@@ -33,7 +33,7 @@ class Mailer < ActionMailer::Base
       @target = cls
     end
     def method_missing(name, *args, &block)
-      if Setting.delayjob_enabled && Object.const_defined?('Delayed::Worker')
+      if Setting.delayjob_enabled && Object.const_defined?('Delayed')
         @target.delay.send(name, *args, &block)
       else
         @target.send(name, *args, &block).deliver