diff --git a/activesupport/lib/active_support/testing/autorun.rb b/activesupport/lib/active_support/testing/autorun.rb
index 5aa5f46310..84c6b89340 100644
--- a/activesupport/lib/active_support/testing/autorun.rb
+++ b/activesupport/lib/active_support/testing/autorun.rb
@@ -2,4 +2,11 @@ gem 'minitest'
 
 require 'minitest'
 
-Minitest.autorun
+if Minitest.respond_to?(:run_with_rails_extension)
+  unless Minitest.run_with_rails_extension
+    Minitest.run_with_autorun = true
+    Minitest.autorun
+  end
+else
+  Minitest.autorun
+end
diff --git a/railties/lib/rails/test_help.rb b/railties/lib/rails/test_help.rb
index 3b444b0932..828039dc43 100644
--- a/railties/lib/rails/test_help.rb
+++ b/railties/lib/rails/test_help.rb
@@ -9,10 +9,7 @@ require 'action_controller/test_case'
 require 'action_dispatch/testing/integration'
 require 'rails/generators/test_case'
 
-unless Minitest.run_with_rails_extension
-  Minitest.run_with_autorun = true
-  require 'active_support/testing/autorun'
-end
+require 'active_support/testing/autorun'
 
 if defined?(ActiveRecord::Base)
   ActiveRecord::Migration.maintain_test_schema!