diff --git a/src/calibre/srv/tests/base.py b/src/calibre/srv/tests/base.py
index fe8e59c5a9..ac3016a896 100644
--- a/src/calibre/srv/tests/base.py
+++ b/src/calibre/srv/tests/base.py
@@ -108,6 +108,7 @@ class TestServer(Thread):
 
     def __exit__(self, *args):
         self.loop.stop()
+        self.join(self.loop.opts.shutdown_timeout)
 
     def connect(self, timeout=None):
         if timeout is None: