diff --git a/examples/debugging/fast_error_in_root_after_spawn.py b/examples/debugging/fast_error_in_root_after_spawn.py
index 044815b..570cf7e 100644
--- a/examples/debugging/fast_error_in_root_after_spawn.py
+++ b/examples/debugging/fast_error_in_root_after_spawn.py
@@ -20,7 +20,7 @@ async def sleep(
 
 
 async def open_ctx(
-    n: tractor._trionics.ActorNursery
+    n: tractor._supervise.ActorNursery
 ):
 
     # spawn both actors