diff --git a/tests/test_debugger.py b/tests/test_debugger.py
index fe357e8..227e8f5 100644
--- a/tests/test_debugger.py
+++ b/tests/test_debugger.py
@@ -41,7 +41,7 @@ def mk_cmd(ex_name: str) -> str:
 def spawn(
     testdir,
     arb_addr,
-) -> pexpect.spawn:
+) -> 'pexpect.spawn':
 
     def _spawn(cmd):
         return testdir.spawn(
@@ -355,7 +355,6 @@ def test_root_nursery_cancels_before_child_releases_tty_lock(spawn):
 
         child.sendline('c')
 
-
     child.expect(pexpect.EOF)
     before = str(child.before.decode())
     assert "tractor._exceptions.RemoteActorError: ('spawner0'" in before