diff --git a/requirements.txt b/requirements.txt
index 3a758e0..89e7ca5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,20 +2,20 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-pbr<2.0,>=1.3
-Babel>=1.3
+pbr!=2.1.0 # Apache-2.0
+Babel!=2.4.0 # BSD
 
 attrdict>=2.0.0
-lxml>=3.4.0
-paramiko>=2.4.2
-prettytable>=0.7.2
-pymongo>=2.7.2
-pytz>=2016.4
-python-glanceclient>=0.15.0
-python-neutronclient>=3.0.0
-python-novaclient>=2.18.1
-python-openstackclient>=0.4.1
-python-keystoneclient>=3.10.0
+lxml!=3.7.0 # BSD
+paramiko # LGPLv2.1+
+PrettyTable<0.8 # BSD
+pymongo!=3.1 # Apache-2.0
+pytz # MIT
+python-glanceclient # Apache-2.0
+python-neutronclient # Apache-2.0
+python-novaclient # Apache-2.0
+python-openstackclient # Apache-2.0
+python-keystoneclient!=2.1.0 # Apache-2.0
 scp>=0.8.0
 tabulate>=0.7.3
 fluent-logger>=0.5.2
diff --git a/setup.py b/setup.py
old mode 100755
new mode 100644
index 70c2b3f..566d844
--- a/setup.py
+++ b/setup.py
@@ -1,4 +1,3 @@
-#!/usr/bin/env python
 # Copyright (c) 2013 Hewlett-Packard Development Company, L.P.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -17,6 +16,14 @@
 # THIS FILE IS MANAGED BY THE GLOBAL REQUIREMENTS REPO - DO NOT EDIT
 import setuptools
 
+# In python < 2.7.4, a lazy loading of package `pbr` will break
+# setuptools if some other modules registered functions in `atexit`.
+# solution from: http://bugs.python.org/issue15881#msg170215
+try:
+    import multiprocessing  # noqa
+except ImportError:
+    pass
+
 setuptools.setup(
-    setup_requires=['pbr'],
+    setup_requires=['pbr>=2.0.0'],
     pbr=True)
diff --git a/test-requirements.txt b/test-requirements.txt
index b4d107d..74f973f 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -2,16 +2,17 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-hacking>=1.1.0,<1.2.0 # Apache-2.0
+hacking<1.2.0,>=1.1.0 # Apache-2.0
 
-coverage>=3.6
+coverage!=4.4 # Apache-2.0
 discover
-python-subunit>=0.0.18
-sphinx>=1.4.0
-sphinx_rtd_theme>=0.1.9
-oslosphinx>=2.5.0  # Apache-2.0
-oslotest>=1.10.0  # Apache-2.0
-testrepository>=0.0.18
-testscenarios>=0.4
-testtools>=1.4.0
-pytest>=3.0.2
\ No newline at end of file
+python-subunit # Apache-2.0/BSD
+sphinx!=1.6.6,!=1.6.7,<2.0.0;python_version=='2.7' # BSD
+sphinx!=1.6.6,!=1.6.7;python_version>='3.4' # BSD
+sphinx-rtd-theme>=0.1.9
+oslosphinx # Apache-2.0
+oslotest # Apache-2.0
+testrepository # Apache-2.0/BSD
+testscenarios # Apache-2.0/BSD
+testtools # MIT
+pytest>=3.0.2
diff --git a/tox.ini b/tox.ini
index 9c5be6e..44952d3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,11 +5,14 @@ skipsdist = True
 
 [testenv]
 usedevelop = True
-install_command = pip install -U {opts} {packages}
+install_command =
+  pip install {opts} {packages}
+deps =
+  -c{env:UPPER_CONSTRAINTS_FILE:https://opendev.org/openstack/requirements/raw/branch/master/upper-constraints.txt}
+  -r{toxinidir}/requirements.txt
+  -r{toxinidir}/test-requirements.txt
 setenv =
    VIRTUAL_ENV={envdir}
-deps = -r{toxinidir}/requirements.txt
-       -r{toxinidir}/test-requirements.txt
 commands = py.test -q -s --basetemp={envtmpdir} {posargs}
 
 [testenv:pep8]