diff --git a/guides/source/testing.md b/guides/source/testing.md
index 94cfcf12b7f947d045eab940e3e2088fc7da1f93..fa55c09c64ccb0e167a379dfc3d111b02af5ad7b 100644
--- a/guides/source/testing.md
+++ b/guides/source/testing.md
@@ -1201,7 +1201,7 @@ within a model:
 ```ruby
 require 'test_helper'
 
-class ProductTest < ActiveSupport::TestCase
+class ProductTest < ActiveJob::TestCase
   test 'billing job scheduling' do
     assert_enqueued_with(job: BillingJob) do
       product.charge(account)