diff --git a/openstackclient/shell.py b/openstackclient/shell.py
index cd5ab552..35d8255d 100644
--- a/openstackclient/shell.py
+++ b/openstackclient/shell.py
@@ -24,7 +24,7 @@ from cliff import app
 from cliff import help
 
 from openstackclient.common import clientmanager
-from openstackclient.common.commandmanager import CommandManager
+from openstackclient.common import commandmanager
 from openstackclient.common import exceptions as exc
 from openstackclient.common import openstackkeyring
 from openstackclient.common import utils
@@ -63,7 +63,7 @@ class OpenStackShell(app.App):
         super(OpenStackShell, self).__init__(
             description=__doc__.strip(),
             version=VERSION,
-            command_manager=CommandManager('openstack.cli'))
+            command_manager=commandmanager.CommandManager('openstack.cli'))
 
         # This is instantiated in initialize_app() only when using
         # password flow auth
diff --git a/tox.ini b/tox.ini
index 9b5a843b..f6de18d1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,8 +11,7 @@ deps = -r{toxinidir}/tools/pip-requires
 commands = python setup.py testr --testr-args='{posargs}'
 
 [testenv:pep8]
-deps = pep8==1.3.3
-commands = pep8 --ignore=E126,E202,W602 --repeat --show-source openstackclient setup.py
+commands = flake8
 
 [testenv:venv]
 commands = {posargs}
@@ -22,3 +21,8 @@ commands = python setup.py testr --coverage --testr-args='{posargs}'
 
 [tox:jenkins]
 downloadcache = ~/cache/pip
+
+[flake8]
+ignore = E126,E202,W602,H402
+show-source = True
+exclude =  .venv,.git,.tox,dist,doc,*openstack/common*,*lib/python*,*egg,build,tools