omg.diff

diff --git a/activesupport/lib/active_support/notifications.rb b/activesupport/lib/active_support/notifications.rb
index b32aa75..7a96c66 100644
--- a/activesupport/lib/active_support/notifications.rb
+++ b/activesupport/lib/active_support/notifications.rb
@@ -178,7 +178,7 @@ module ActiveSupport
       end
 
       def instrumenter
-        InstrumentationRegistry.instrumenter_for(notifier)
+        InstrumentationRegistry.instance.instrumenter_for(notifier)
       end
     end
 
diff --git a/activesupport/lib/active_support/per_thread_registry.rb b/activesupport/lib/active_support/per_thread_registry.rb
index aa682fb..1cb9740 100644
--- a/activesupport/lib/active_support/per_thread_registry.rb
+++ b/activesupport/lib/active_support/per_thread_registry.rb
@@ -48,5 +48,6 @@ module ActiveSupport
       def per_thread_registry_instance
         Thread.current[name] ||= new
       end
+      alias :instance :per_thread_registry_instance
   end
 end