3 files changed, 13 insertions, 6 deletions
diff --git a/actionmailer/lib/action_mailer/parameterized.rb b/actionmailer/lib/action_mailer/parameterized.rb
index 999435919e..0a97af8105 100644
--- a/actionmailer/lib/action_mailer/parameterized.rb
+++ b/actionmailer/lib/action_mailer/parameterized.rb
@@ -145,12 +145,20 @@ module ActionMailer
           if processed?
             super
           else
-            job  = @mailer_class.delivery_job
+            job  = delivery_job_class
             args = arguments_for(job, delivery_method)
             job.set(options).perform_later(*args)
           end
         end
 
+        def delivery_job_class
+          if @mailer_class.delivery_job <= MailDeliveryJob
+            @mailer_class.delivery_job
+          else
+            Parameterized::DeliveryJob
+          end
+        end
+
         def arguments_for(delivery_job, delivery_method)
           if delivery_job <= MailDeliveryJob
             [@mailer_class.name, @action.to_s, delivery_method.to_s, params: @params, args: @args]
diff --git a/actionmailer/test/abstract_unit.rb b/actionmailer/test/abstract_unit.rb
index f647896374..448807c144 100644
--- a/actionmailer/test/abstract_unit.rb
+++ b/actionmailer/test/abstract_unit.rb
@@ -33,6 +33,8 @@ I18n.enforce_available_locales = false
 FIXTURE_LOAD_PATH = File.expand_path("fixtures", __dir__)
 ActionMailer::Base.view_paths = FIXTURE_LOAD_PATH
 
+ActionMailer::Base.delivery_job = ActionMailer::MailDeliveryJob
+
 class ActiveSupport::TestCase
   include ActiveSupport::Testing::MethodCallAssertions
 
diff --git a/actionmailer/test/legacy_delivery_job_test.rb b/actionmailer/test/legacy_delivery_job_test.rb
index 112c842beb..3a3872df47 100644
--- a/actionmailer/test/legacy_delivery_job_test.rb
+++ b/actionmailer/test/legacy_delivery_job_test.rb
@@ -11,9 +11,6 @@ class LegacyDeliveryJobTest < ActiveSupport::TestCase
   class LegacyDeliveryJob < ActionMailer::DeliveryJob
   end
 
-  class LegacyParmeterizedDeliveryJob < ActionMailer::Parameterized::DeliveryJob
-  end
-
   setup do
     @previous_logger = ActiveJob::Base.logger
     ActiveJob::Base.logger = Logger.new(nil)
@@ -42,9 +39,9 @@ class LegacyDeliveryJobTest < ActiveSupport::TestCase
       { inviter: "david@basecamp.com", invitee: "jason@basecamp.com" },
     ]
 
-    with_delivery_job(LegacyParmeterizedDeliveryJob) do
+    with_delivery_job(LegacyDeliveryJob) do
       assert_deprecated do
-        assert_performed_with(job: LegacyParmeterizedDeliveryJob, args: args) do
+        assert_performed_with(job: ActionMailer::Parameterized::DeliveryJob, args: args) do
           mail.deliver_later
         end
       end