diff --git a/tox.ini b/tox.ini
index 406cee4..e23dbc8 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,31 +1,38 @@
 [tox]
-minversion = 3.1.1
+minversion = 3.18.0
 envlist = py3,pypy,pep8
-skipsdist = True
 ignore_basepython_conflict = True
 
 [testenv]
 basepython = python3
+sitepackages = False
 usedevelop = True
-install_command = pip install -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master} {opts} {packages}
 setenv =
    VIRTUAL_ENV={envdir}
    PYTHONWARNINGS=default::DeprecationWarning
    OS_STDOUT_CAPTURE=1
    OS_STDERR_CAPTURE=1
    OS_TEST_TIMEOUT=60
-deps = -r{toxinidir}/test-requirements.txt
+deps =
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -r{toxinidir}/requirements.txt
+
 commands = stestr run {posargs}
 
 [testenv:pep8]
+deps = hacking>=3.0,<3.1.0
 commands = flake8 {posargs}
 
 [testenv:venv]
 commands = {posargs}
 
 [testenv:docs]
+deps =
+  -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -r{toxinidir}/doc/requirements.txt
 commands =
   sphinx-build -a -E -W -b html doc/source doc/build/html
+setenv = PYTHONHASHSEED=0
 
 [testenv:releasenotes]
 commands =