diff --git a/requirements.txt b/requirements.txt
index fd0ed15e..61f422e7 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,7 @@
-appdirs>=1.3.0  # MIT License
+# The order of packages is significant, because pip processes them in the order
+# of appearance. Changing the order has an impact on the overall integration
+# process, which may cause wedges in the gate later.
+appdirs>=1.3.0 # MIT License
 PyYAML>=3.1.0
 six>=1.9.0
-stevedore>=1.5.0  # Apache 2.0
+stevedore>=1.5.0 # Apache-2.0
diff --git a/setup.py b/setup.py
old mode 100755
new mode 100644
index 70c2b3f3..782bb21f
--- 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>=1.8'],
     pbr=True)
diff --git a/test-requirements.txt b/test-requirements.txt
index c75708ff..56716826 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -1,13 +1,16 @@
+# The order of packages is significant, because pip processes them in the order
+# of appearance. Changing the order has an impact on the overall integration
+# process, which may cause wedges in the gate later.
 coverage>=3.6
 discover
-fixtures>=0.3.14
-hacking>=0.9.2,<0.10
-mock>=1.0
+fixtures>=1.3.1
+hacking<0.10,>=0.9.2
+mock>=1.2
 python-subunit>=0.0.18
 testrepository>=0.0.18
 testscenarios>=0.4
-testtools>=0.9.36,!=1.2.0
+testtools>=1.4.0
 
-sphinx>=1.1.2,!=1.2.0,!=1.3b1,<1.3
-oslosphinx>=2.5.0  # Apache-2.0
+sphinx!=1.2.0,!=1.3b1,<1.3,>=1.1.2
+oslosphinx>=2.5.0 # Apache-2.0
 beautifulsoup4