diff --git a/neutron/agent/dhcp_agent.py b/neutron/agent/dhcp_agent.py
index b6da1d31f77..371d37c3e03 100644
--- a/neutron/agent/dhcp_agent.py
+++ b/neutron/agent/dhcp_agent.py
@@ -30,6 +30,7 @@ from neutron import service as neutron_service
 
 
 def register_options(conf):
+    common_config.register_common_config_options()
     config.register_interface_driver_opts_helper(conf)
     config.register_agent_state_opts_helper(conf)
     config.register_availability_zone_opts_helper(conf)
diff --git a/neutron/agent/l3/keepalived_state_change.py b/neutron/agent/l3/keepalived_state_change.py
index eb0650b6cf5..9bb97696fea 100644
--- a/neutron/agent/l3/keepalived_state_change.py
+++ b/neutron/agent/l3/keepalived_state_change.py
@@ -166,6 +166,7 @@ class MonitorDaemon(daemon.Daemon):
 
 
 def configure(conf):
+    config.register_common_config_options()
     config.init(sys.argv[1:])
     conf.set_override('log_dir', cfg.CONF.conf_dir)
     conf.set_override('debug', True)
diff --git a/neutron/agent/l3_agent.py b/neutron/agent/l3_agent.py
index d79e8cc6e48..0b8b704698e 100644
--- a/neutron/agent/l3_agent.py
+++ b/neutron/agent/l3_agent.py
@@ -31,6 +31,7 @@ from neutron import service as neutron_service
 
 
 def register_opts(conf):
+    common_config.register_common_config_options()
     l3_config.register_l3_agent_config_opts(l3_config.OPTS, conf)
     ha_conf.register_l3_agent_ha_opts(conf)
     meta_conf.register_meta_conf_opts(meta_conf.SHARED_OPTS, conf)
diff --git a/neutron/agent/metadata_agent.py b/neutron/agent/metadata_agent.py
index e6265b42e1b..feee9917340 100644
--- a/neutron/agent/metadata_agent.py
+++ b/neutron/agent/metadata_agent.py
@@ -29,6 +29,7 @@ LOG = logging.getLogger(__name__)
 
 
 def main():
+    config.register_common_config_options()
     meta.register_meta_conf_opts(meta.SHARED_OPTS)
     meta.register_meta_conf_opts(meta.UNIX_DOMAIN_METADATA_PROXY_OPTS)
     meta.register_meta_conf_opts(meta.METADATA_PROXY_HANDLER_OPTS)
diff --git a/neutron/agent/ovn/metadata_agent.py b/neutron/agent/ovn/metadata_agent.py
index 3b0656368d0..8afaf0cef5b 100644
--- a/neutron/agent/ovn/metadata_agent.py
+++ b/neutron/agent/ovn/metadata_agent.py
@@ -26,6 +26,7 @@ LOG = logging.getLogger(__name__)
 
 
 def main():
+    config.register_common_config_options()
     ovn_meta.register_meta_conf_opts(meta.SHARED_OPTS)
     ovn_meta.register_meta_conf_opts(meta.UNIX_DOMAIN_METADATA_PROXY_OPTS)
     ovn_meta.register_meta_conf_opts(meta.METADATA_PROXY_HANDLER_OPTS)
diff --git a/neutron/cmd/destroy_patch_ports.py b/neutron/cmd/destroy_patch_ports.py
index 81dd7bef023..2fa6dc4acda 100644
--- a/neutron/cmd/destroy_patch_ports.py
+++ b/neutron/cmd/destroy_patch_ports.py
@@ -78,6 +78,7 @@ class PatchPortCleaner(object):
 
 
 def main():
+    common_config.register_common_config_options()
     common_config.init(sys.argv[1:])
     ovs_conf.register_ovs_agent_opts()
     common_config.setup_logging()
diff --git a/neutron/cmd/eventlet/usage_audit.py b/neutron/cmd/eventlet/usage_audit.py
index 4d1435af4c6..010134c4fe4 100644
--- a/neutron/cmd/eventlet/usage_audit.py
+++ b/neutron/cmd/eventlet/usage_audit.py
@@ -29,6 +29,7 @@ from neutron import manager
 
 
 def main():
+    config.register_common_config_options()
     config.init(sys.argv[1:])
     config.setup_logging()
 
diff --git a/neutron/cmd/ipset_cleanup.py b/neutron/cmd/ipset_cleanup.py
index 7f09b8d9c57..2ee65a8d867 100644
--- a/neutron/cmd/ipset_cleanup.py
+++ b/neutron/cmd/ipset_cleanup.py
@@ -32,6 +32,7 @@ def setup_conf():
     from the main config that do not apply during clean-up.
     """
     conf = cfg.CONF
+    config.register_common_config_options()
     agent_config.register_root_helper(conf=conf)
     agent_config.setup_privsep()
     command.register_cmd_opts(command.ip_opts, conf)
diff --git a/neutron/cmd/linuxbridge_cleanup.py b/neutron/cmd/linuxbridge_cleanup.py
index 34e22ce3847..5338b0984d1 100644
--- a/neutron/cmd/linuxbridge_cleanup.py
+++ b/neutron/cmd/linuxbridge_cleanup.py
@@ -16,6 +16,7 @@ from neutron_lib.utils import helpers
 from oslo_config import cfg
 from oslo_log import log as logging
 
+from neutron.common import config as common_config
 from neutron.conf.agent import common as config
 from neutron.plugins.ml2.drivers.linuxbridge.agent \
     import linuxbridge_neutron_agent
@@ -67,6 +68,7 @@ def main():
     This tool should not be called during an instance create, migrate, etc. as
     it can delete a linux bridge about to be used by nova.
     """
+    common_config.register_common_config_options()
     cfg.CONF(sys.argv[1:])
     config.setup_logging()
     config.setup_privsep()
diff --git a/neutron/cmd/netns_cleanup.py b/neutron/cmd/netns_cleanup.py
index a12987228a1..ac5ddfddd25 100644
--- a/neutron/cmd/netns_cleanup.py
+++ b/neutron/cmd/netns_cleanup.py
@@ -66,6 +66,7 @@ def setup_conf():
     """
 
     conf = cfg.CONF
+    config.register_common_config_options()
     cmd.register_cmd_opts(cmd.netns_opts, conf)
     agent_config.register_interface_driver_opts_helper(conf)
     dhcp_config.register_agent_dhcp_opts(conf)
diff --git a/neutron/cmd/ovn/neutron_ovn_db_sync_util.py b/neutron/cmd/ovn/neutron_ovn_db_sync_util.py
index 274eb29ab34..9370cabe4fd 100644
--- a/neutron/cmd/ovn/neutron_ovn_db_sync_util.py
+++ b/neutron/cmd/ovn/neutron_ovn_db_sync_util.py
@@ -20,6 +20,7 @@ from oslo_config import cfg
 from oslo_db import options as db_options
 from oslo_log import log as logging
 
+from neutron.common import config as common_config
 from neutron.conf.agent import securitygroups_rpc
 from neutron.conf.plugins.ml2.drivers.ovn import ovn_conf
 from neutron import manager
@@ -137,6 +138,7 @@ class AgentNotifierApi(object):
 
 def setup_conf():
     conf = cfg.CONF
+    common_config.register_common_config_options()
     ml2_group, ml2_opts = neutron_options.list_ml2_conf_opts()[0]
     cfg.CONF.register_cli_opts(ml2_opts, ml2_group)
     cfg.CONF.register_cli_opts(securitygroups_rpc.security_group_opts,
diff --git a/neutron/cmd/ovs_cleanup.py b/neutron/cmd/ovs_cleanup.py
index 8e75317e08f..8c6e1dd2cbc 100644
--- a/neutron/cmd/ovs_cleanup.py
+++ b/neutron/cmd/ovs_cleanup.py
@@ -39,6 +39,7 @@ def setup_conf():
     """
 
     conf = cfg.CONF
+    config.register_common_config_options()
     cmd.register_cmd_opts(cmd.ovs_opts, conf)
     l3_config.register_l3_agent_config_opts(l3_config.OPTS, conf)
     agent_config.register_interface_driver_opts_helper(conf)
diff --git a/neutron/cmd/sanitize_port_binding_profile_allocation.py b/neutron/cmd/sanitize_port_binding_profile_allocation.py
index 87077ef7a82..c482301d90f 100644
--- a/neutron/cmd/sanitize_port_binding_profile_allocation.py
+++ b/neutron/cmd/sanitize_port_binding_profile_allocation.py
@@ -19,6 +19,7 @@ from oslo_db import options as db_options
 from oslo_log import log as logging
 
 from neutron.api import converters as n_converters
+from neutron.common import config as common_config
 from neutron.objects import ports as port_obj
 from neutron.objects.qos import binding as qos_binding_obj
 from neutron.objects.qos import rule as qos_rule_obj
@@ -29,6 +30,7 @@ LOG = logging.getLogger(__name__)
 
 def setup_conf():
     conf = cfg.CONF
+    common_config.register_common_config_options()
     db_group, neutron_db_opts = db_options.list_opts()[0]
     cfg.CONF.register_cli_opts(neutron_db_opts, db_group)
     conf()
diff --git a/neutron/cmd/sanitize_port_mac_addresses.py b/neutron/cmd/sanitize_port_mac_addresses.py
index 61762e5350e..20af0a605e3 100644
--- a/neutron/cmd/sanitize_port_mac_addresses.py
+++ b/neutron/cmd/sanitize_port_mac_addresses.py
@@ -17,6 +17,7 @@ from oslo_config import cfg
 from oslo_db import options as db_options
 from oslo_log import log as logging
 
+from neutron.common import config as common_config
 from neutron.db import models_v2
 
 
@@ -25,6 +26,7 @@ LOG = logging.getLogger(__name__)
 
 def setup_conf():
     conf = cfg.CONF
+    common_config.register_common_config_options()
     db_group, neutron_db_opts = db_options.list_opts()[0]
     cfg.CONF.register_cli_opts(neutron_db_opts, db_group)
     conf()
diff --git a/neutron/cmd/sanity_check.py b/neutron/cmd/sanity_check.py
index db19f15cdee..69af3f5a501 100644
--- a/neutron/cmd/sanity_check.py
+++ b/neutron/cmd/sanity_check.py
@@ -37,6 +37,7 @@ LOG = logging.getLogger(__name__)
 
 
 def setup_conf():
+    config.register_common_config_options()
     ovs_conf.register_ovs_agent_opts(cfg.CONF)
     lb_conf.register_linuxbridge_opts(cfg.CONF)
     sriov_conf.register_agent_sriov_nic_opts(cfg.CONF)
diff --git a/neutron/cmd/status.py b/neutron/cmd/status.py
index b25435a2d18..4941b6b589b 100644
--- a/neutron/cmd/status.py
+++ b/neutron/cmd/status.py
@@ -18,6 +18,7 @@ from oslo_db import options as db_options
 from oslo_log import log as logging
 from oslo_upgradecheck import upgradecheck
 
+from neutron.common import config as common_config
 from neutron.conf import common as neutron_conf_base
 from neutron.conf import service as neutron_conf_service
 
@@ -50,7 +51,7 @@ def setup_conf(conf=cfg.CONF):
     Use separate setup_conf for the utility because there are many options
     from the main config that do not apply during checks.
     """
-
+    common_config.register_common_config_options()
     neutron_conf_base.register_core_common_config_opts(conf)
     neutron_conf_service.register_service_opts(
         neutron_conf_service.SERVICE_OPTS, cfg.CONF)
diff --git a/neutron/common/config.py b/neutron/common/config.py
index 5eaae86ed64..bd2f0e037f6 100644
--- a/neutron/common/config.py
+++ b/neutron/common/config.py
@@ -37,6 +37,8 @@ from neutron import version
 
 LOG = logging.getLogger(__name__)
 
+_COMMON_OPTIONS_ALREADY_REGISTERED = False
+
 # Jam here any extra log level default you care about. This helps keep
 # Neutron logs lean.
 EXTRA_LOG_LEVEL_DEFAULTS = [
@@ -46,40 +48,46 @@ EXTRA_LOG_LEVEL_DEFAULTS = [
     'os_ken.controller.controller=INFO',
 ]
 
-# Register the configuration options
-common_config.register_core_common_config_opts()
 
-# Ensure that the control exchange is set correctly
-oslo_messaging.set_transport_defaults(control_exchange='neutron')
+def register_common_config_options():
+    global _COMMON_OPTIONS_ALREADY_REGISTERED
+    if _COMMON_OPTIONS_ALREADY_REGISTERED:
+        return
 
+    # Register the configuration options
+    common_config.register_core_common_config_opts()
 
-NOVA_CONF_SECTION = 'nova'
+    # Ensure that the control exchange is set correctly
+    oslo_messaging.set_transport_defaults(control_exchange='neutron')
 
-ks_loading.register_auth_conf_options(cfg.CONF, NOVA_CONF_SECTION)
-ks_loading.register_session_conf_options(cfg.CONF, NOVA_CONF_SECTION)
+    ks_loading.register_auth_conf_options(
+        cfg.CONF, common_config.NOVA_CONF_SECTION)
+    ks_loading.register_session_conf_options(
+        cfg.CONF, common_config.NOVA_CONF_SECTION)
 
+    # Register the nova configuration options
+    common_config.register_nova_opts()
 
-# Register the nova configuration options
-common_config.register_nova_opts()
+    ks_loading.register_auth_conf_options(cfg.CONF,
+                                          common_config.PLACEMENT_CONF_SECTION)
+    ks_loading.register_session_conf_options(
+        cfg.CONF, common_config.PLACEMENT_CONF_SECTION)
 
-ks_loading.register_auth_conf_options(cfg.CONF,
-                                      common_config.PLACEMENT_CONF_SECTION)
-ks_loading.register_session_conf_options(cfg.CONF,
-                                         common_config.PLACEMENT_CONF_SECTION)
+    # Register the placement configuration options
+    common_config.register_placement_opts()
 
-# Register the placement configuration options
-common_config.register_placement_opts()
+    logging.register_options(cfg.CONF)
 
-logging.register_options(cfg.CONF)
+    # Register the ironic configuration options
+    ks_loading.register_auth_conf_options(cfg.CONF,
+                                          common_config.IRONIC_CONF_SECTION)
+    ks_loading.register_session_conf_options(cfg.CONF,
+                                             common_config.IRONIC_CONF_SECTION)
+    ks_loading.register_adapter_conf_options(cfg.CONF,
+                                             common_config.IRONIC_CONF_SECTION)
+    common_config.register_ironic_opts()
 
-# Register the ironic configuration options
-ks_loading.register_auth_conf_options(cfg.CONF,
-                                      common_config.IRONIC_CONF_SECTION)
-ks_loading.register_session_conf_options(cfg.CONF,
-                                         common_config.IRONIC_CONF_SECTION)
-ks_loading.register_adapter_conf_options(cfg.CONF,
-                                         common_config.IRONIC_CONF_SECTION)
-common_config.register_ironic_opts()
+    _COMMON_OPTIONS_ALREADY_REGISTERED = True
 
 
 def init(args, default_config_files=None, **kwargs):
diff --git a/neutron/db/migration/cli.py b/neutron/db/migration/cli.py
index 4948e902a48..7ec867349e3 100644
--- a/neutron/db/migration/cli.py
+++ b/neutron/db/migration/cli.py
@@ -27,6 +27,7 @@ from oslo_utils import fileutils
 from oslo_utils import importutils
 
 from neutron._i18n import _
+from neutron.common import config as common_config
 from neutron.conf.db import migration_cli
 from neutron.db import migration
 from neutron.db.migration.connection import DBConnection
@@ -651,6 +652,7 @@ def get_engine_config():
 
 
 def main():
+    common_config.register_common_config_options()
     # Interpret the config file for Python logging.
     # This line sets up loggers basically.
     logging_config.fileConfig(neutron_alembic_ini)
diff --git a/neutron/debug/shell.py b/neutron/debug/shell.py
index 37b5a7e65ae..25715ac0841 100644
--- a/neutron/debug/shell.py
+++ b/neutron/debug/shell.py
@@ -20,6 +20,7 @@ from oslo_utils import importutils
 
 from neutron._i18n import _
 from neutron.agent.common import utils
+from neutron.common import config as common_config
 from neutron.conf.agent import common as config
 from neutron.conf.plugins.ml2.drivers import ovs_conf
 from neutron.debug import debug_agent
@@ -86,5 +87,6 @@ class NeutronDebugShell(shell.NeutronShell):
 
 
 def main(argv=None):
+    common_config.register_common_config_options()
     return NeutronDebugShell(shell.NEUTRON_API_VERSION).run(
         argv or sys.argv[1:])
diff --git a/neutron/plugins/ml2/drivers/linuxbridge/agent/linuxbridge_neutron_agent.py b/neutron/plugins/ml2/drivers/linuxbridge/agent/linuxbridge_neutron_agent.py
index 39d8d879967..1c11f0c82fc 100644
--- a/neutron/plugins/ml2/drivers/linuxbridge/agent/linuxbridge_neutron_agent.py
+++ b/neutron/plugins/ml2/drivers/linuxbridge/agent/linuxbridge_neutron_agent.py
@@ -1012,6 +1012,7 @@ class LinuxBridgeRpcCallbacks(sg_rpc.SecurityGroupAgentRpcCallbackMixin,
 
 
 def main():
+    common_config.register_common_config_options()
     common_config.init(sys.argv[1:])
 
     common_config.setup_logging()
diff --git a/neutron/plugins/ml2/drivers/macvtap/agent/macvtap_neutron_agent.py b/neutron/plugins/ml2/drivers/macvtap/agent/macvtap_neutron_agent.py
index af1f5d586d2..8255d1eb067 100644
--- a/neutron/plugins/ml2/drivers/macvtap/agent/macvtap_neutron_agent.py
+++ b/neutron/plugins/ml2/drivers/macvtap/agent/macvtap_neutron_agent.py
@@ -206,6 +206,7 @@ def validate_firewall_driver():
 
 
 def main():
+    common_config.register_common_config_options()
     common_config.init(sys.argv[1:])
 
     common_config.setup_logging()
diff --git a/neutron/plugins/ml2/drivers/mech_sriov/agent/sriov_nic_agent.py b/neutron/plugins/ml2/drivers/mech_sriov/agent/sriov_nic_agent.py
index e0e0b30291a..e552aba48a1 100644
--- a/neutron/plugins/ml2/drivers/mech_sriov/agent/sriov_nic_agent.py
+++ b/neutron/plugins/ml2/drivers/mech_sriov/agent/sriov_nic_agent.py
@@ -537,6 +537,7 @@ class SriovNicAgentConfigParser(object):
 
 
 def main():
+    common_config.register_common_config_options()
     common_config.init(sys.argv[1:])
 
     common_config.setup_logging()
diff --git a/neutron/plugins/ml2/drivers/openvswitch/agent/main.py b/neutron/plugins/ml2/drivers/openvswitch/agent/main.py
index 59709f3638f..9d5911e21d3 100644
--- a/neutron/plugins/ml2/drivers/openvswitch/agent/main.py
+++ b/neutron/plugins/ml2/drivers/openvswitch/agent/main.py
@@ -30,6 +30,7 @@ cfg.CONF.import_group('OVS', 'neutron.plugins.ml2.drivers.openvswitch.agent.'
 
 
 def main():
+    common_config.register_common_config_options()
     common_config.init(sys.argv[1:])
     of_main.init_config()
     common_config.setup_logging()
diff --git a/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py b/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py
index 1b52efd187d..29bfd4a5128 100644
--- a/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py
+++ b/neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py
@@ -646,7 +646,9 @@ class OVSNeutronAgent(l2population_rpc.L2populationRpcCallBackTunnelMixin,
 
     def _add_port_to_updated_smartnic_ports(self, mac, vif_name, iface_id,
                         vif_type, vm_uuid='',
-                        mtu=plugin_utils.get_deployment_physnet_mtu()):
+                        mtu=None):
+        if mtu is None:
+            mtu = plugin_utils.get_deployment_physnet_mtu()
         self.updated_smartnic_ports.append({
             'mac': mac,
             'vm_uuid': vm_uuid,
diff --git a/neutron/server/__init__.py b/neutron/server/__init__.py
index f3cbe17c2c5..db729626ec1 100644
--- a/neutron/server/__init__.py
+++ b/neutron/server/__init__.py
@@ -52,7 +52,7 @@ def _get_config_files(env=None):
 def _init_configuration():
     # the configuration will be read into the cfg.CONF global data structure
     conf_files = _get_config_files()
-
+    config.register_common_config_options()
     config.init(sys.argv[1:], default_config_files=conf_files)
     config.setup_logging()
     config.set_config_defaults()
diff --git a/neutron/services/metering/agents/metering_agent.py b/neutron/services/metering/agents/metering_agent.py
index 1bc950d2ffd..36600202e4c 100644
--- a/neutron/services/metering/agents/metering_agent.py
+++ b/neutron/services/metering/agents/metering_agent.py
@@ -395,6 +395,7 @@ class MeteringAgentWithStateReport(MeteringAgent):
 
 def main():
     conf = cfg.CONF
+    common_config.register_common_config_options()
     metering_agent.register_metering_agent_opts()
     config.register_agent_state_opts_helper(conf)
     common_config.init(sys.argv[1:])
diff --git a/neutron/tests/base.py b/neutron/tests/base.py
index 14aa07a77ff..7e5d9bb7c71 100644
--- a/neutron/tests/base.py
+++ b/neutron/tests/base.py
@@ -62,7 +62,6 @@ from neutron.tests import post_mortem_debug
 
 
 CONF = cfg.CONF
-CONF.import_opt('state_path', 'neutron.conf.common')
 
 ROOTDIR = os.path.dirname(__file__)
 ETCDIR = os.path.join(ROOTDIR, 'etc')
@@ -383,6 +382,7 @@ class BaseTestCase(DietTestCase):
         self.useFixture(lockutils.ExternalLockFixture())
         self.useFixture(fixture.APIDefinitionFixture())
 
+        config.register_common_config_options()
         cfg.CONF.set_override('state_path', self.get_default_temp_dir().path)
 
         self.addCleanup(CONF.reset)
diff --git a/neutron/tests/fullstack/agents/dhcp_agent.py b/neutron/tests/fullstack/agents/dhcp_agent.py
index dc1ea5fb70d..d4159f5fd99 100755
--- a/neutron/tests/fullstack/agents/dhcp_agent.py
+++ b/neutron/tests/fullstack/agents/dhcp_agent.py
@@ -22,6 +22,7 @@ from oslo_utils import uuidutils
 
 from neutron.agent.linux import dhcp as linux_dhcp
 from neutron.cmd.eventlet.agents import dhcp as dhcp_agent
+from neutron.common import config
 
 
 OPTS = [
@@ -76,6 +77,7 @@ def monkeypatch_linux_dhcp():
 
 
 def main():
+    config.register_common_config_options()
     cfg.CONF.register_opts(OPTS)
     monkeypatch_linux_dhcp()
     dhcp_agent.main()
diff --git a/neutron/tests/fullstack/agents/l3_agent.py b/neutron/tests/fullstack/agents/l3_agent.py
index ebc50399f7a..d685d893a21 100755
--- a/neutron/tests/fullstack/agents/l3_agent.py
+++ b/neutron/tests/fullstack/agents/l3_agent.py
@@ -17,10 +17,12 @@ import sys
 
 from oslo_config import cfg  # noqa
 
+from neutron.common import config
 from neutron.common import eventlet_utils
 from neutron.tests.common.agents import l3_agent
 
 eventlet_utils.monkey_patch()
 
 if __name__ == "__main__":
+    config.register_common_config_options()
     sys.exit(l3_agent.main())
diff --git a/neutron/tests/fullstack/agents/ovs_agent.py b/neutron/tests/fullstack/agents/ovs_agent.py
index f10559ba963..6f73ca78c8e 100755
--- a/neutron/tests/fullstack/agents/ovs_agent.py
+++ b/neutron/tests/fullstack/agents/ovs_agent.py
@@ -21,6 +21,7 @@ from oslo_config import cfg
 from neutron.agent.common import ovs_lib
 from neutron.agent.common import polling
 from neutron.agent.l2.extensions import qos as qos_extension
+from neutron.common import config
 from neutron.services.trunk.drivers.openvswitch.agent \
     import driver as trunk_driver
 from neutron.tests.common.agents import ovs_agent
@@ -61,6 +62,7 @@ def main():
     # https://review.opendev.org/#/c/506722/ will be merged and ovsdb-server
     # ovs-vswitchd processes for each test will be isolated in separate
     # namespace
+    config.register_common_config_options()
     monkeypatch_init_handler()
     monkeypatch_qos()
     monkeypatch_event_filtering()
diff --git a/neutron/tests/fullstack/servers/placement.py b/neutron/tests/fullstack/servers/placement.py
index c19eab327f9..fce770b707c 100755
--- a/neutron/tests/fullstack/servers/placement.py
+++ b/neutron/tests/fullstack/servers/placement.py
@@ -135,6 +135,7 @@ class FakePlacement(object):
 
 
 if __name__ == "__main__":
+    common_config.register_common_config_options()
     common_config.init(sys.argv[1:])
     common_config.setup_logging()
     placement_port = cfg.CONF.placement_port
diff --git a/neutron/tests/functional/db/test_migrations.py b/neutron/tests/functional/db/test_migrations.py
index 037b6fdc811..34c4e1fea84 100644
--- a/neutron/tests/functional/db/test_migrations.py
+++ b/neutron/tests/functional/db/test_migrations.py
@@ -27,6 +27,7 @@ import sqlalchemy
 from sqlalchemy import event  # noqa
 from sqlalchemy.sql import ddl as sqla_ddl
 
+from neutron.common import config
 from neutron.db import migration as migration_root
 from neutron.db.migration.alembic_migrations import external
 from neutron.db.migration import cli as migration
@@ -35,7 +36,6 @@ from neutron.tests import base as test_base
 from neutron.tests.functional import base as functional_base
 from neutron.tests.unit import testlib_api
 
-cfg.CONF.import_opt('core_plugin', 'neutron.conf.common')
 
 CREATION_OPERATIONS = {
     'sqla': (sqla_ddl.CreateIndex,
@@ -143,6 +143,7 @@ class _TestModelsMigrations(test_migrations.ModelsMigrationsSync):
     TIMEOUT_SCALING_FACTOR = 4
 
     def setUp(self):
+        config.register_common_config_options()
         super(_TestModelsMigrations, self).setUp()
         self.cfg = self.useFixture(config_fixture.Config())
         self.cfg.config(core_plugin='ml2')