diff --git a/greentest/test__hub.py b/greentest/test__hub.py
index a3cd09bef0d0ec11e24f2aa6ecc5874e1c412429..90712368a1e7090639955c2933a53337919bce0d 100644
--- a/greentest/test__hub.py
+++ b/greentest/test__hub.py
@@ -98,7 +98,7 @@ class TestShutdown(unittest.TestCase):
 
     def test(self):
         # make sure Hub is started. For the test case when hub is not started, see test_hub_shutdown.py
-
+        gevent.sleep(0)
         assert not gevent.hub.get_hub().dead
         self._shutdown()
         self.assert_no_hub()