diff --git a/hooks/nova_cc_hooks.py b/hooks/nova_cc_hooks.py
index 51e0242b..287cf48b 100755
--- a/hooks/nova_cc_hooks.py
+++ b/hooks/nova_cc_hooks.py
@@ -654,6 +654,7 @@ def get_compute_config(remote_restart=False):
         # this may not even be needed.
         'ec2_host': hookenv.unit_get('private-address'),
         'region': hookenv.config('region'),
+        'cross_az_attach': hookenv.config('cross-az-attach'),
     }
     rel_settings.update(console_settings())
     rel_settings.update(ncc_utils.serial_console_settings())
@@ -719,6 +720,18 @@ def set_region_on_relation_from_config(rid=None):
     hookenv.relation_set(relation_id=rid, region=hookenv.config('region'))
 
 
+def set_cross_az_attach_on_relation_from_config(rid=None):
+    """Helper function that sets the cross-az-attach policy for that relation
+    to trigger a change for any units that see it differently.
+
+    :param rid: The relation to set, or if None, the current one related
+                to the hook.
+    :type rid: Union[str, None]
+    """
+    hookenv.relation_set(relation_id=rid,
+                         cross_az_attach=hookenv.config('cross-az-attach'))
+
+
 def update_ssh_keys_and_notify_compute_units(rid=None, unit=None):
     """Update and notify the collected ssh keys to nova-compute units
 
@@ -1174,6 +1187,7 @@ def upgrade_charm():
         identity_joined(rid=r_id)
     for r_id in hookenv.relation_ids('cloud-compute'):
         set_region_on_relation_from_config(r_id)
+        set_cross_az_attach_on_relation_from_config(r_id)
         for unit in hookenv.related_units(r_id):
             update_ssh_keys_and_notify_compute_units(r_id, unit)
     for r_id in hookenv.relation_ids('shared-db'):
diff --git a/unit_tests/test_nova_cc_hooks.py b/unit_tests/test_nova_cc_hooks.py
index 0a7d3dbf..b5415cd0 100644
--- a/unit_tests/test_nova_cc_hooks.py
+++ b/unit_tests/test_nova_cc_hooks.py
@@ -615,6 +615,7 @@ class NovaCCHooksTests(CharmTestCase):
             console_access_protocol=None,
             ca_cert='foocert64',
             region='RegionOne',
+            cross_az_attach=True,
             volume_service='cinder',
             ec2_host='nova-cc-host1',
             network_manager='neutron',
@@ -657,6 +658,7 @@ class NovaCCHooksTests(CharmTestCase):
             quantum_host='nova-cc-host1',
             quantum_security_groups='yes',
             region='RegionOne',
+            cross_az_attach=True,
             volume_service='cinder',
             ec2_host='nova-cc-host1',
             quantum_plugin='bob',