diff --git a/nova/cloudpipe/pipelib.py b/nova/cloudpipe/pipelib.py
index 4e498e2c91d..206ce183593 100644
--- a/nova/cloudpipe/pipelib.py
+++ b/nova/cloudpipe/pipelib.py
@@ -52,6 +52,7 @@
                help=_('Netmask to push into openvpn config')),
     ]
 
+flags.DECLARE('cnt_vpn_clients', 'nova.network.manager')
 FLAGS = flags.FLAGS
 FLAGS.register_opts(cloudpipe_opts)