diff --git a/railties/lib/rails_generator/generators/components/observer/templates/unit_test.rb b/railties/lib/rails_generator/generators/components/observer/templates/unit_test.rb
index cae38e9a2a..03f6d5666e 100644
--- a/railties/lib/rails_generator/generators/components/observer/templates/unit_test.rb
+++ b/railties/lib/rails_generator/generators/components/observer/templates/unit_test.rb
@@ -1,6 +1,6 @@
 require 'test_helper'
 
-class <%= class_name %>ObserverTest < Test::Unit::TestCase
+class <%= class_name %>ObserverTest < ActiveSupport::TestCase
   # Replace this with your real tests.
   test "the truth" do
     assert true