diff --git a/zaza/openstack/utilities/openstack.py b/zaza/openstack/utilities/openstack.py
index 729f524..464d49c 100644
--- a/zaza/openstack/utilities/openstack.py
+++ b/zaza/openstack/utilities/openstack.py
@@ -485,14 +485,13 @@ def get_admin_net(neutron_client):
 
 
 def _plumb_guest_nic(server_name, mac_address, dvr_mode=None):
-    """In guest server_name, add port with mac_address to netplan
+    """In guest server_name, add port with mac_address to netplan.
 
     :param server_name: Hostname of instance
     :type server_name: string
     :param mac_address: mac address of nic to be added to netplan
     :type mac_address: string
     """
-
     if dvr_mode:
         application_name = 'neutron-openvswitch'
     else: