diff --git a/tractor/_actor.py b/tractor/_actor.py
index 048d7b4e..a2be2150 100644
--- a/tractor/_actor.py
+++ b/tractor/_actor.py
@@ -1006,6 +1006,7 @@ class Actor:
     def is_infected_aio(self) -> bool:
         return self._infected_aio
 
+
 class Arbiter(Actor):
     """A special actor who knows all the other actors and always has
     access to a top level nursery.