diff --git a/tox.ini b/tox.ini
index c0944289..f9cde4a2 100644
--- a/tox.ini
+++ b/tox.ini
@@ -13,7 +13,7 @@ deps = -r{toxinidir}/tools/pip-requires
 commands = nosetests
 
 [testenv:pep8]
-commands = pep8 --repeat --show-source glanceclient setup.py
+commands = pep8 --repeat --show-source glanceclient tests setup.py
 
 [testenv:venv]
 commands = {posargs}