diff --git a/bin/nova-manage b/bin/nova-manage
index 1b77ede467..8d3e9cd4e2 100755
--- a/bin/nova-manage
+++ b/bin/nova-manage
@@ -47,7 +47,7 @@ class VpnCommands(object):
 
             vpn = self.__vpn_for(project.id)
             if vpn:
-                out, err = utils.execute("ping -c1 -w1 %s > /dev/null; echo $?", vpn['private_dns_name'])
+                out, err = utils.execute("ping -c1 -w1 %s > /dev/null; echo $?" % vpn['private_dns_name'])
                 if out.strip() == '0':
                     net = 'up'
                 else: