diff --git a/ironic/api/controllers/v1/driver.py b/ironic/api/controllers/v1/driver.py
index aa06b5bfb9..d41903e35c 100644
--- a/ironic/api/controllers/v1/driver.py
+++ b/ironic/api/controllers/v1/driver.py
@@ -23,6 +23,7 @@ import wsmeext.pecan as wsme_pecan
 from ironic.api.controllers import base
 from ironic.api.controllers import link
 from ironic.common import exception
+from ironic.common.i18n import _
 
 
 # Property information for drivers:
diff --git a/ironic/api/controllers/v1/node.py b/ironic/api/controllers/v1/node.py
index 5c3db703e7..ddf5ea9678 100644
--- a/ironic/api/controllers/v1/node.py
+++ b/ironic/api/controllers/v1/node.py
@@ -30,6 +30,7 @@ from ironic.api.controllers.v1 import port
 from ironic.api.controllers.v1 import types
 from ironic.api.controllers.v1 import utils as api_utils
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.common import states as ir_states
 from ironic.common import utils
 from ironic import objects
diff --git a/ironic/api/controllers/v1/port.py b/ironic/api/controllers/v1/port.py
index 623e414d50..0433448cb9 100644
--- a/ironic/api/controllers/v1/port.py
+++ b/ironic/api/controllers/v1/port.py
@@ -28,6 +28,7 @@ from ironic.api.controllers.v1 import collection
 from ironic.api.controllers.v1 import types
 from ironic.api.controllers.v1 import utils as api_utils
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic import objects
 
 
diff --git a/ironic/api/controllers/v1/types.py b/ironic/api/controllers/v1/types.py
index 8c3187b1d4..31eb4cb72a 100644
--- a/ironic/api/controllers/v1/types.py
+++ b/ironic/api/controllers/v1/types.py
@@ -20,6 +20,7 @@ import wsme
 from wsme import types as wtypes
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.common import utils
 
 
diff --git a/ironic/api/controllers/v1/utils.py b/ironic/api/controllers/v1/utils.py
index ff1be250f7..0ffe29e281 100644
--- a/ironic/api/controllers/v1/utils.py
+++ b/ironic/api/controllers/v1/utils.py
@@ -18,6 +18,8 @@ import wsme
 
 from oslo.config import cfg
 
+from ironic.common.i18n import _
+
 CONF = cfg.CONF
 
 
diff --git a/ironic/api/middleware/auth_token.py b/ironic/api/middleware/auth_token.py
index d30f5d9ab9..539b0359d0 100644
--- a/ironic/api/middleware/auth_token.py
+++ b/ironic/api/middleware/auth_token.py
@@ -17,6 +17,7 @@ import re
 from keystonemiddleware import auth_token
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.common import utils
 from ironic.openstack.common import log
 
diff --git a/ironic/api/middleware/parsable_error.py b/ironic/api/middleware/parsable_error.py
index 4b947f2cad..49de04a938 100644
--- a/ironic/api/middleware/parsable_error.py
+++ b/ironic/api/middleware/parsable_error.py
@@ -26,6 +26,7 @@ import json
 import webob
 from xml import etree as et
 
+from ironic.common.i18n import _
 from ironic.openstack.common import log
 
 LOG = log.getLogger(__name__)
diff --git a/ironic/cmd/api.py b/ironic/cmd/api.py
index 3b43543876..8aace6cb43 100644
--- a/ironic/cmd/api.py
+++ b/ironic/cmd/api.py
@@ -25,6 +25,7 @@ from six.moves import socketserver
 from wsgiref import simple_server
 
 from ironic.api import app
+from ironic.common.i18n import _
 from ironic.common import service as ironic_service
 from ironic.openstack.common import log
 
diff --git a/ironic/common/disk_partitioner.py b/ironic/common/disk_partitioner.py
index 6b8e695159..7703d17a6a 100644
--- a/ironic/common/disk_partitioner.py
+++ b/ironic/common/disk_partitioner.py
@@ -18,6 +18,7 @@ import re
 from oslo.config import cfg
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.common import utils
 from ironic.openstack.common import log as logging
 from ironic.openstack.common import loopingcall
diff --git a/ironic/common/driver_factory.py b/ironic/common/driver_factory.py
index 446ab2155f..d93a5cedc1 100644
--- a/ironic/common/driver_factory.py
+++ b/ironic/common/driver_factory.py
@@ -16,6 +16,7 @@
 from oslo.config import cfg
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.openstack.common import lockutils
 from ironic.openstack.common import log
 from stevedore import dispatch
diff --git a/ironic/common/glance_service/base_image_service.py b/ironic/common/glance_service/base_image_service.py
index a6eea191d9..447cba34e7 100644
--- a/ironic/common/glance_service/base_image_service.py
+++ b/ironic/common/glance_service/base_image_service.py
@@ -28,6 +28,7 @@ import six.moves.urllib.parse as urlparse
 
 from ironic.common import exception
 from ironic.common.glance_service import service_utils
+from ironic.common.i18n import _
 
 from oslo.config import cfg
 
diff --git a/ironic/common/glance_service/v2/image_service.py b/ironic/common/glance_service/v2/image_service.py
index d9785a858f..030dbc3e8f 100644
--- a/ironic/common/glance_service/v2/image_service.py
+++ b/ironic/common/glance_service/v2/image_service.py
@@ -20,6 +20,7 @@ from ironic.common import exception as exc
 from ironic.common.glance_service import base_image_service
 from ironic.common.glance_service import service
 from ironic.common.glance_service import service_utils
+from ironic.common.i18n import _
 from ironic.common import utils
 
 
diff --git a/ironic/common/hash_ring.py b/ironic/common/hash_ring.py
index 00f272ffd2..db3081fcad 100644
--- a/ironic/common/hash_ring.py
+++ b/ironic/common/hash_ring.py
@@ -21,6 +21,7 @@ import threading
 from oslo.config import cfg
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.db import api as dbapi
 
 hash_opts = [
diff --git a/ironic/common/images.py b/ironic/common/images.py
index 54f8ed6869..bceea1f110 100644
--- a/ironic/common/images.py
+++ b/ironic/common/images.py
@@ -27,6 +27,7 @@ from oslo.config import cfg
 
 from ironic.common import exception
 from ironic.common import i18n
+from ironic.common.i18n import _
 from ironic.common import image_service as service
 from ironic.common import paths
 from ironic.common import utils
diff --git a/ironic/common/keystone.py b/ironic/common/keystone.py
index 8f785ac1cc..41de23aba5 100644
--- a/ironic/common/keystone.py
+++ b/ironic/common/keystone.py
@@ -19,6 +19,7 @@ from oslo.config import cfg
 from six.moves.urllib import parse
 
 from ironic.common import exception
+from ironic.common.i18n import _
 
 CONF = cfg.CONF
 
diff --git a/ironic/common/service.py b/ironic/common/service.py
index b313e8196c..078092c684 100644
--- a/ironic/common/service.py
+++ b/ironic/common/service.py
@@ -23,6 +23,7 @@ from oslo import messaging
 from oslo.utils import importutils
 
 from ironic.common import config
+from ironic.common.i18n import _
 from ironic.common import rpc
 from ironic.objects import base as objects_base
 from ironic.openstack.common import context
diff --git a/ironic/common/swift.py b/ironic/common/swift.py
index c5f0e9f8c4..d414ace94d 100644
--- a/ironic/common/swift.py
+++ b/ironic/common/swift.py
@@ -21,6 +21,7 @@ from swiftclient import exceptions as swift_exceptions
 from swiftclient import utils as swift_utils
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.common import keystone
 from ironic.openstack.common import log as logging
 
diff --git a/ironic/common/utils.py b/ironic/common/utils.py
index 917f3a62d7..713ad67831 100644
--- a/ironic/common/utils.py
+++ b/ironic/common/utils.py
@@ -34,6 +34,7 @@ import paramiko
 import six
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.openstack.common import log as logging
 from ironic.openstack.common import processutils
 
diff --git a/ironic/conductor/manager.py b/ironic/conductor/manager.py
index eaca1b2be9..e2712306e1 100644
--- a/ironic/conductor/manager.py
+++ b/ironic/conductor/manager.py
@@ -57,6 +57,7 @@ from ironic.common import driver_factory
 from ironic.common import exception
 from ironic.common import hash_ring as hash
 from ironic.common import i18n
+from ironic.common.i18n import _
 from ironic.common import rpc
 from ironic.common import states
 from ironic.common import utils as ironic_utils
diff --git a/ironic/conductor/rpcapi.py b/ironic/conductor/rpcapi.py
index 177424a931..a2b19e1953 100644
--- a/ironic/conductor/rpcapi.py
+++ b/ironic/conductor/rpcapi.py
@@ -24,6 +24,7 @@ from oslo import messaging
 
 from ironic.common import exception
 from ironic.common import hash_ring as hash
+from ironic.common.i18n import _
 from ironic.common import rpc
 from ironic.conductor import manager
 from ironic.objects import base as objects_base
diff --git a/ironic/conductor/utils.py b/ironic/conductor/utils.py
index c78af0ce12..c90072d88c 100644
--- a/ironic/conductor/utils.py
+++ b/ironic/conductor/utils.py
@@ -15,6 +15,7 @@
 from oslo.utils import excutils
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.common import states
 from ironic.conductor import task_manager
 from ironic.openstack.common.gettextutils import _LI
diff --git a/ironic/db/sqlalchemy/api.py b/ironic/db/sqlalchemy/api.py
index ef33f47d8d..839b638f9a 100644
--- a/ironic/db/sqlalchemy/api.py
+++ b/ironic/db/sqlalchemy/api.py
@@ -27,6 +27,7 @@ from oslo.utils import timeutils
 from sqlalchemy.orm.exc import NoResultFound
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.common import states
 from ironic.common import utils
 from ironic.db import api
diff --git a/ironic/dhcp/neutron.py b/ironic/dhcp/neutron.py
index d940281168..e54066f668 100644
--- a/ironic/dhcp/neutron.py
+++ b/ironic/dhcp/neutron.py
@@ -22,6 +22,7 @@ from oslo.config import cfg
 
 from ironic.common import exception
 from ironic.common import i18n
+from ironic.common.i18n import _
 from ironic.common import keystone
 from ironic.common import network
 from ironic.dhcp import base
diff --git a/ironic/drivers/base.py b/ironic/drivers/base.py
index 7b4c1f9298..520069b77e 100644
--- a/ironic/drivers/base.py
+++ b/ironic/drivers/base.py
@@ -22,6 +22,7 @@ import abc
 import six
 
 from ironic.common import exception
+from ironic.common.i18n import _
 
 
 @six.add_metaclass(abc.ABCMeta)
diff --git a/ironic/drivers/drac.py b/ironic/drivers/drac.py
index 869230dd4f..1d8a80de26 100644
--- a/ironic/drivers/drac.py
+++ b/ironic/drivers/drac.py
@@ -15,6 +15,7 @@ DRAC Driver for remote system management using Dell Remote Access Card.
 """
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.drivers import base
 from ironic.drivers.modules.drac import power
 from ironic.drivers.modules import ipmitool
diff --git a/ironic/drivers/fake.py b/ironic/drivers/fake.py
index 7d4e7cfd20..d230b69940 100644
--- a/ironic/drivers/fake.py
+++ b/ironic/drivers/fake.py
@@ -20,6 +20,7 @@ Fake drivers used in testing.
 from oslo.utils import importutils
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.drivers import base
 from ironic.drivers.modules import agent
 from ironic.drivers.modules.drac import power as drac_power
diff --git a/ironic/drivers/modules/agent.py b/ironic/drivers/modules/agent.py
index d07ce5145c..ba60a3d570 100644
--- a/ironic/drivers/modules/agent.py
+++ b/ironic/drivers/modules/agent.py
@@ -21,6 +21,7 @@ from oslo.utils import excutils
 from ironic.common import dhcp_factory
 from ironic.common import exception
 from ironic.common import i18n
+from ironic.common.i18n import _
 from ironic.common import image_service
 from ironic.common import keystone
 from ironic.common import paths
diff --git a/ironic/drivers/modules/agent_client.py b/ironic/drivers/modules/agent_client.py
index 9b57c4472a..b07b29be96 100644
--- a/ironic/drivers/modules/agent_client.py
+++ b/ironic/drivers/modules/agent_client.py
@@ -16,6 +16,7 @@ from oslo.config import cfg
 import requests
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.openstack.common import jsonutils
 from ironic.openstack.common import log
 
diff --git a/ironic/drivers/modules/console_utils.py b/ironic/drivers/modules/console_utils.py
index 081b35e63f..21648e9da9 100644
--- a/ironic/drivers/modules/console_utils.py
+++ b/ironic/drivers/modules/console_utils.py
@@ -28,6 +28,7 @@ from oslo.config import cfg
 
 from ironic.common import exception
 from ironic.common import i18n
+from ironic.common.i18n import _
 from ironic.common import utils
 from ironic.openstack.common import log as logging
 from ironic.openstack.common import loopingcall
diff --git a/ironic/drivers/modules/deploy_utils.py b/ironic/drivers/modules/deploy_utils.py
index 58a1337de7..898d211103 100644
--- a/ironic/drivers/modules/deploy_utils.py
+++ b/ironic/drivers/modules/deploy_utils.py
@@ -25,6 +25,7 @@ from oslo.utils import excutils
 
 from ironic.common import disk_partitioner
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.common import utils
 from ironic.drivers.modules import image_cache
 from ironic.openstack.common import log as logging
@@ -153,9 +154,9 @@ def mkfs_ephemeral(dev, ephemeral_format, label="ephemeral0"):
 
 def block_uuid(dev):
     """Get UUID of a block device."""
-    out, _ = utils.execute('blkid', '-s', 'UUID', '-o', 'value', dev,
-                           run_as_root=True,
-                           check_exit_code=[0])
+    out, _err = utils.execute('blkid', '-s', 'UUID', '-o', 'value', dev,
+                              run_as_root=True,
+                              check_exit_code=[0])
     return out.strip()
 
 
diff --git a/ironic/drivers/modules/drac/common.py b/ironic/drivers/modules/drac/common.py
index a9ae83765d..dd61d615de 100644
--- a/ironic/drivers/modules/drac/common.py
+++ b/ironic/drivers/modules/drac/common.py
@@ -16,6 +16,7 @@ Common functionalities shared between different DRAC modules.
 """
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.drivers.modules.drac import client as drac_client
 from ironic.openstack.common import importutils
 
diff --git a/ironic/drivers/modules/fake.py b/ironic/drivers/modules/fake.py
index 6474a8d928..55f00e4ff5 100644
--- a/ironic/drivers/modules/fake.py
+++ b/ironic/drivers/modules/fake.py
@@ -26,6 +26,7 @@ on seprate vendor_passthru methods.
 
 from ironic.common import boot_devices
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.common import states
 from ironic.drivers import base
 
diff --git a/ironic/drivers/modules/iboot.py b/ironic/drivers/modules/iboot.py
index 836187a519..b2760bfed1 100644
--- a/ironic/drivers/modules/iboot.py
+++ b/ironic/drivers/modules/iboot.py
@@ -23,6 +23,7 @@ from oslo.utils import importutils
 
 from ironic.common import exception
 from ironic.common import i18n
+from ironic.common.i18n import _
 from ironic.common import states
 from ironic.conductor import task_manager
 from ironic.drivers import base
diff --git a/ironic/drivers/modules/ilo/common.py b/ironic/drivers/modules/ilo/common.py
index 26650ee1e7..30bf6c76e2 100644
--- a/ironic/drivers/modules/ilo/common.py
+++ b/ironic/drivers/modules/ilo/common.py
@@ -20,6 +20,7 @@ from oslo.config import cfg
 from oslo.utils import importutils
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.openstack.common import log as logging
 
 ilo_client = importutils.try_import('proliantutils.ilo.ribcl')
diff --git a/ironic/drivers/modules/ilo/power.py b/ironic/drivers/modules/ilo/power.py
index e6465da923..0fb0594979 100644
--- a/ironic/drivers/modules/ilo/power.py
+++ b/ironic/drivers/modules/ilo/power.py
@@ -20,6 +20,7 @@ from oslo.config import cfg
 from oslo.utils import importutils
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.common import states
 from ironic.conductor import task_manager
 from ironic.drivers import base
diff --git a/ironic/drivers/modules/image_cache.py b/ironic/drivers/modules/image_cache.py
index b1e8a91c4a..c125948ea2 100644
--- a/ironic/drivers/modules/image_cache.py
+++ b/ironic/drivers/modules/image_cache.py
@@ -26,6 +26,7 @@ from oslo.config import cfg
 
 from ironic.common import exception
 from ironic.common.glance_service import service_utils
+from ironic.common.i18n import _
 from ironic.common import images
 from ironic.common import utils
 from ironic.openstack.common import fileutils
diff --git a/ironic/drivers/modules/ipminative.py b/ironic/drivers/modules/ipminative.py
index 517132a4be..e032c7a73e 100644
--- a/ironic/drivers/modules/ipminative.py
+++ b/ironic/drivers/modules/ipminative.py
@@ -25,6 +25,7 @@ from oslo.utils import importutils
 from ironic.common import boot_devices
 from ironic.common import exception
 from ironic.common import i18n
+from ironic.common.i18n import _
 from ironic.common import states
 from ironic.conductor import task_manager
 from ironic.drivers import base
diff --git a/ironic/drivers/modules/ipmitool.py b/ironic/drivers/modules/ipmitool.py
index 60b308a1ab..c7e878da0b 100644
--- a/ironic/drivers/modules/ipmitool.py
+++ b/ironic/drivers/modules/ipmitool.py
@@ -42,6 +42,7 @@ from oslo.utils import excutils
 from ironic.common import boot_devices
 from ironic.common import exception
 from ironic.common import i18n
+from ironic.common.i18n import _
 from ironic.common import states
 from ironic.common import utils
 from ironic.conductor import task_manager
diff --git a/ironic/drivers/modules/iscsi_deploy.py b/ironic/drivers/modules/iscsi_deploy.py
index 8d5de84c23..620de68594 100644
--- a/ironic/drivers/modules/iscsi_deploy.py
+++ b/ironic/drivers/modules/iscsi_deploy.py
@@ -19,6 +19,7 @@ from oslo.config import cfg
 
 from ironic.common import exception
 from ironic.common import i18n
+from ironic.common.i18n import _
 from ironic.common import image_service as service
 from ironic.common import keystone
 from ironic.common import states
diff --git a/ironic/drivers/modules/pxe.py b/ironic/drivers/modules/pxe.py
index 82a535bce9..60501a2c58 100644
--- a/ironic/drivers/modules/pxe.py
+++ b/ironic/drivers/modules/pxe.py
@@ -25,6 +25,7 @@ from oslo.config import cfg
 from ironic.common import dhcp_factory
 from ironic.common import exception
 from ironic.common import i18n
+from ironic.common.i18n import _
 from ironic.common import image_service as service
 from ironic.common import paths
 from ironic.common import pxe_utils
diff --git a/ironic/drivers/modules/seamicro.py b/ironic/drivers/modules/seamicro.py
index 5aa29d6faa..5628bec725 100644
--- a/ironic/drivers/modules/seamicro.py
+++ b/ironic/drivers/modules/seamicro.py
@@ -25,6 +25,7 @@ from oslo.utils import importutils
 from ironic.common import boot_devices
 from ironic.common import exception
 from ironic.common import i18n
+from ironic.common.i18n import _
 from ironic.common import states
 from ironic.conductor import task_manager
 from ironic.drivers import base
diff --git a/ironic/drivers/modules/ssh.py b/ironic/drivers/modules/ssh.py
index 09b372678c..ee5c825a23 100644
--- a/ironic/drivers/modules/ssh.py
+++ b/ironic/drivers/modules/ssh.py
@@ -33,12 +33,12 @@ from oslo.config import cfg
 from ironic.common import boot_devices
 from ironic.common import exception
 from ironic.common import i18n
+from ironic.common.i18n import _
 from ironic.common import states
 from ironic.common import utils
 from ironic.conductor import task_manager
 from ironic.drivers import base
 from ironic.drivers import utils as driver_utils
-from ironic.openstack.common.gettextutils import _
 from ironic.openstack.common import log as logging
 from ironic.openstack.common import processutils
 
diff --git a/ironic/drivers/pxe.py b/ironic/drivers/pxe.py
index 8d81df4377..8737341158 100644
--- a/ironic/drivers/pxe.py
+++ b/ironic/drivers/pxe.py
@@ -20,6 +20,7 @@ PXE Driver and supporting meta-classes.
 from oslo.utils import importutils
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.drivers import base
 from ironic.drivers.modules import iboot
 from ironic.drivers.modules.ilo import power as ilo_power
diff --git a/ironic/drivers/utils.py b/ironic/drivers/utils.py
index c91045440a..ad1c9cfd07 100644
--- a/ironic/drivers/utils.py
+++ b/ironic/drivers/utils.py
@@ -13,6 +13,7 @@
 # under the License.
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.drivers import base
 
 
diff --git a/ironic/objects/base.py b/ironic/objects/base.py
index 2254d0076c..b67836f7b6 100644
--- a/ironic/objects/base.py
+++ b/ironic/objects/base.py
@@ -21,6 +21,7 @@ from oslo import messaging
 import six
 
 from ironic.common import exception
+from ironic.common.i18n import _
 from ironic.objects import utils as obj_utils
 from ironic.openstack.common import context
 from ironic.openstack.common import log as logging
diff --git a/ironic/objects/conductor.py b/ironic/objects/conductor.py
index 6a1ce7e6c2..c7b9c5eef8 100644
--- a/ironic/objects/conductor.py
+++ b/ironic/objects/conductor.py
@@ -14,6 +14,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from ironic.common.i18n import _
 from ironic.db import api as db_api
 from ironic.objects import base
 from ironic.objects import utils
diff --git a/ironic/objects/utils.py b/ironic/objects/utils.py
index c9761f0e61..2a15a4b828 100644
--- a/ironic/objects/utils.py
+++ b/ironic/objects/utils.py
@@ -22,6 +22,8 @@ import netaddr
 from oslo.utils import timeutils
 import six
 
+from ironic.common.i18n import _
+
 
 def datetime_or_none(dt):
     """Validate a datetime or None value."""
diff --git a/ironic/tests/db/sqlalchemy/test_migrations.py b/ironic/tests/db/sqlalchemy/test_migrations.py
index 001599b60b..1c2533593a 100644
--- a/ironic/tests/db/sqlalchemy/test_migrations.py
+++ b/ironic/tests/db/sqlalchemy/test_migrations.py
@@ -49,6 +49,7 @@ from oslo.db.sqlalchemy import utils as db_utils
 import sqlalchemy
 import sqlalchemy.exc
 
+from ironic.common.i18n import _
 from ironic.common import utils
 from ironic.db.sqlalchemy import migration
 from ironic.db.sqlalchemy import models
diff --git a/tox.ini b/tox.ini
index 76e94f49c1..04f732f0d3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -43,7 +43,6 @@ commands = {posargs}
 
 ignore = E12,E711
 select = E713
-builtins = _
 exclude =  .venv,.git,.tox,dist,doc,*openstack/common*,*lib/python*,*egg,build,tools,*ironic/nova*
 
 [hacking]