diff --git a/kubespawner/spawner.py b/kubespawner/spawner.py
index 612613d22..2679190a8 100644
--- a/kubespawner/spawner.py
+++ b/kubespawner/spawner.py
@@ -14,7 +14,7 @@
 from tornado import gen
 from tornado.ioloop import IOLoop
 from tornado.concurrent import run_on_executor
-from traitlets import Type, Unicode, List, Integer, Union, Dict, Bool, Any
+from traitlets import Type, Unicode, List, Integer, Union, Dict, Bool, Any, Instance
 from jupyterhub.spawner import Spawner
 from jupyterhub.utils import exponential_backoff
 from jupyterhub.traitlets import Command
@@ -47,7 +47,7 @@ def pods(self):
 
 class EventReflector(NamespacedResourceReflector):
     kind = 'events'
-    queue = Queue(20)
+    queue = Instance(Queue, args=(20,))
 
     list_method_name = 'list_namespaced_event'