diff --git a/ansible/site.yml b/ansible/site.yml
index e467686060..4c17417920 100644
--- a/ansible/site.yml
+++ b/ansible/site.yml
@@ -324,6 +324,7 @@
 - name: Apply role opendaylight
   gather_facts: false
   hosts: opendaylight
+  serial: '{{ serial|default("0") }}'
   roles:
     - { role: opendaylight,
         tags: opendaylight,
@@ -332,6 +333,7 @@
 - name: Apply role openvswitch
   hosts:
     - openvswitch
+  serial: '{{ serial|default("0") }}'
   roles:
     - { role: openvswitch,
         tags: openvswitch,
@@ -340,6 +342,7 @@
 - name: Apply role ovs-dpdk
   hosts:
     - openvswitch
+  serial: '{{ serial|default("0") }}'
   roles:
     - { role: ovs-dpdk,
         tags: ovs-dpdk,
@@ -378,6 +381,7 @@
   gather_facts: false
   hosts:
     - compute
+  serial: '{{ serial|default("0") }}'
   roles:
     - { role: kuryr,
         tags: kuryr,