diff --git a/tox.ini b/tox.ini
index 5f7bb3d..1a71742 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,42 +1,23 @@
 [tox]
 minversion = 2.0
-envlist = py34-constraints,py27-constraints,pypy-constraints,pep8-constraints
-skipsdist = True
+envlist = py{27,34,35},pep8
 
 [testenv]
-usedevelop = True
-install_command =
-                  constraints: {[testenv:common-constraints]install_command}
-                  pip install -U {opts} {packages}
-setenv =
-   VIRTUAL_ENV={envdir}
-deps = -r{toxinidir}/test-requirements.txt
+install_command = pip install {opts} {packages}
+deps =
+  -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
+  -r{toxinidir}/test-requirements.txt
 commands = python setup.py testr --slowest --testr-args='{posargs}'
 
-[testenv:common-constraints]
-install_command = pip install -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} {opts} {packages}
-
 [testenv:pep8]
 commands = flake8 {posargs}
 
-[testenv:pep8-constraints]
-install_command = {[testenv:common-constraints]install_command}
-commands = flake8 {posargs}
-
 [testenv:venv]
 commands = {posargs}
 
-[testenv:venv-constraints]
-install_command = {[testenv:common-constraints]install_command}
-commands = {posargs}
-
 [testenv:cover]
 commands = python setup.py test --coverage --testr-args='{posargs}'
 
-[testenv:cover-constraints]
-install_command = {[testenv:common-constraints]install_command}
-commands = python setup.py test --coverage --testr-args='{posargs}'
-
 [testenv:docs]
 commands = python setup.py build_sphinx
 
@@ -44,20 +25,11 @@ commands = python setup.py build_sphinx
 commands =
   sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
-[testenv:docs-constraints]
-install_command = {[testenv:common-constraints]install_command}
-commands = python setup.py build_sphinx
-
 [testenv:debug]
 commands = oslo_debug_helper {posargs}
 
-[testenv:debug-constraints]
-install_command = {[testenv:common-constraints]install_command}
-commands = oslo_debug_helper {posargs}
-
 [flake8]
 # E123, E125 skipped as they are invalid PEP-8.
-
 show-source = True
 ignore = E123,E125,H405
 builtins = _