diff --git a/xos/openstack/driver.py b/xos/openstack/driver.py
index 02d49f9..15668b9 100644
--- a/xos/openstack/driver.py
+++ b/xos/openstack/driver.py
@@ -45,6 +45,8 @@
     def admin_driver(self, tenant=None, controller=None):
         if isinstance(controller, int):
             controller = Controller.objects.get(id=controller.id)
+        if not tenant:
+            tenant = controller.admin_tenant
         client = OpenStackClient(tenant=tenant, controller=controller, cacert=self.config.nova_ca_ssl_cert)
         driver = OpenStackDriver(client=client)
         driver.admin_user = client.keystone.users.find(name=controller.admin_user)
diff --git a/xos/openstack_observer/steps/sync_ports.py b/xos/openstack_observer/steps/sync_ports.py
index 18e0d00..6b1be57 100644
--- a/xos/openstack_observer/steps/sync_ports.py
+++ b/xos/openstack_observer/steps/sync_ports.py
@@ -50,7 +50,7 @@
                 logger.info("controller %s has no admin_tenant" % controller)
                 continue
             try:
-                driver = self.driver.admin_driver(controller = controller,tenant='admin')
+                driver = self.driver.admin_driver(controller = controller)
                 ports = driver.shell.quantum.list_ports()["ports"]
             except:
                 logger.log_exc("failed to get ports from controller %s" % controller)