diff --git a/nova/api/openstack/__init__.py b/nova/api/openstack/__init__.py
index b2f57e7d22df..4438fb238b44 100644
--- a/nova/api/openstack/__init__.py
+++ b/nova/api/openstack/__init__.py
@@ -20,7 +20,6 @@ WSGI middleware for OpenStack API controllers.
 
 from oslo_log import log as logging
 import routes
-import six
 import stevedore
 import webob.dec
 import webob.exc
@@ -54,7 +53,7 @@ class FaultWrapper(base_wsgi.Middleware):
                                   status, webob.exc.HTTPInternalServerError)()
 
     def _error(self, inner, req):
-        LOG.exception(_LE("Caught error: %s"), six.text_type(inner))
+        LOG.exception(_LE("Caught error: %s"), inner)
 
         safe = getattr(inner, 'safe', False)
         headers = getattr(inner, 'headers', None)
diff --git a/nova/cmd/api.py b/nova/cmd/api.py
index c127f0d22859..19e09407814d 100644
--- a/nova/cmd/api.py
+++ b/nova/cmd/api.py
@@ -24,7 +24,6 @@ import sys
 
 from oslo_log import log as logging
 from oslo_reports import guru_meditation_report as gmr
-import six
 
 import nova.conf
 from nova import config
@@ -63,7 +62,7 @@ def main():
         except exception.PasteAppNotFound as ex:
             log.warning(
                 _LW("%s. ``enabled_apis`` includes bad values. "
-                    "Fix to remove this warning."), six.text_type(ex))
+                    "Fix to remove this warning."), ex)
 
     if started == 0:
         log.error(_LE('No APIs were started. '
diff --git a/nova/network/security_group/neutron_driver.py b/nova/network/security_group/neutron_driver.py
index 21f2c76ceff0..91d5b9a598a5 100644
--- a/nova/network/security_group/neutron_driver.py
+++ b/nova/network/security_group/neutron_driver.py
@@ -243,7 +243,7 @@ class SecurityGroupAPI(security_group_base.SecurityGroupBase):
                                   "group %s"), name)
                 self.raise_over_quota(six.text_type(e))
             elif e.status_code == 400:
-                LOG.exception(_LE("Neutron Error: %s"), six.text_type(e))
+                LOG.exception(_LE("Neutron Error: %s"), e)
                 self.raise_invalid_property(six.text_type(e))
             else:
                 LOG.exception(_LE("Neutron Error:"))