diff --git a/src/wormhole/servers/relay_server.py b/src/wormhole/servers/relay_server.py
index d4aa598..411b76c 100644
--- a/src/wormhole/servers/relay_server.py
+++ b/src/wormhole/servers/relay_server.py
@@ -1,6 +1,7 @@
 from __future__ import print_function
 import re, json, time, random
 from twisted.python import log
+from twisted.application import service, internet
 from twisted.web import server, resource, http
 
 SECONDS = 1.0
@@ -10,6 +11,7 @@ DAY = 24*HOUR
 MB = 1000*1000
 
 CHANNEL_EXPIRATION_TIME = 3*DAY
+EXPIRATION_CHECK_PERIOD = 2*HOUR
 
 class EventsProtocol:
     def __init__(self, request):
@@ -191,12 +193,17 @@ class ChannelList(resource.Resource):
                 "channel-ids": allocated}
         return (json.dumps(data)+"\n").encode("utf-8")
 
-class Relay(resource.Resource):
+class Relay(resource.Resource, service.MultiService):
     def __init__(self, db, welcome):
         resource.Resource.__init__(self)
+        service.MultiService.__init__(self)
         self.db = db
         self.welcome = welcome
         self.channels = {}
+        t = internet.TimerService(EXPIRATION_CHECK_PERIOD,
+                                  self.prune_old_channels)
+        t.setServiceParent(self)
+
 
     def getChild(self, path, request):
         if path == b"allocate":
diff --git a/src/wormhole/servers/server.py b/src/wormhole/servers/server.py
index 493b0e2..3354745 100644
--- a/src/wormhole/servers/server.py
+++ b/src/wormhole/servers/server.py
@@ -1,6 +1,6 @@
 from __future__ import print_function
 from twisted.internet import reactor, endpoints
-from twisted.application import service, internet
+from twisted.application import service
 from twisted.web import server, static, resource
 from ..util.endpoint_service import ServerEndpointService
 from .. import __version__
@@ -8,11 +8,6 @@ from ..database import get_db
 from .relay_server import Relay
 from .transit_server import Transit
 
-SECONDS = 1.0
-MINUTE = 60*SECONDS
-HOUR = 60*MINUTE
-EXPIRATION_CHECK_PERIOD = 2*HOUR
-
 class Root(resource.Resource):
     # child_FOO is a nevow thing, not a twisted.web.resource thing
     def __init__(self):
@@ -42,9 +37,6 @@ class RelayServer(service.MultiService):
         self.relayport_service.setServiceParent(self)
         self.relay = Relay(self.db, welcome) # accessible from tests
         self.root.putChild(b"wormhole-relay", self.relay)
-        t = internet.TimerService(EXPIRATION_CHECK_PERIOD,
-                                  self.relay.prune_old_channels)
-        t.setServiceParent(self)
         if transitport:
             self.transit = Transit()
             self.transit.setServiceParent(self) # for the timer