diff --git a/Lib/test/test_asyncio/test_unix_events.py b/Lib/test/test_asyncio/test_unix_events.py
index f7f992fcea49f9..462a8b3c785917 100644
--- a/Lib/test/test_asyncio/test_unix_events.py
+++ b/Lib/test/test_asyncio/test_unix_events.py
@@ -1836,6 +1836,7 @@ def f():
             policy.get_event_loop().close()
 
         policy = self.create_policy()
+        policy.set_child_watcher(asyncio.SafeChildWatcher())
 
         th = threading.Thread(target=f)
         th.start()