diff --git a/src/allmydata/test/common.py b/src/allmydata/test/common.py
index 6bf2f9743..17f6842a4 100644
--- a/src/allmydata/test/common.py
+++ b/src/allmydata/test/common.py
@@ -453,7 +453,8 @@ class SystemTestMixin(pollmixin.PollMixin, testutil.StallMixin):
 
     def tearDown(self):
         log.msg("shutting down SystemTest services")
-        d = self.sparent.stopService()
+        d = self.stall(0.001)
+        d.addCallback(lambda _: self.sparent.stopService())
         d.addBoth(flush_but_dont_ignore)
         return d