diff --git a/tox.ini b/tox.ini
index c888992..847adad 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
-minversion = 2.0
-envlist = py34,py27,pypy,pep8
+minversion = 1.6
+envlist = py35,py27,pypy,pep8
 skipsdist = True
 
 [testenv]
@@ -9,8 +9,13 @@
 setenv =
    VIRTUAL_ENV={envdir}
    PYTHONWARNINGS=default::DeprecationWarning
-deps = -r{toxinidir}/test-requirements.txt
-commands = python setup.py test --slowest --testr-args='{posargs}'
+passenv = OS_STDOUT_CAPTURE OS_STDERR_CAPTURE OS_TEST_TIMEOUT OS_TEST_LOCK_PATH OS_TEST_PATH TEMPEST_CONFIG TEMPEST_CONFIG_DIR http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
+whitelist_externals = *
+deps = -r{toxinidir}/requirements.txt
+       -r{toxinidir}/test-requirements.txt
+commands = 
+    find . -type f -name "*.pyc" -delete
+    ostestr {posargs}
 
 [testenv:pep8]
 commands = flake8 {posargs}