diff --git a/requirements.txt b/requirements.txt
index 95901f2e0..6d3cdda4c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,13 +1,13 @@
 requests>=1.1
 stevedore>=0.14
 ordereddict
-pecan==0.5.0
+pecan>=0.4.5
 WSME>=0.6
-six>=1.5.2
+six>=1.6.0
 eventlet>=0.13.0
 oslo.config>=1.2.0
 Babel>=1.3
 iso8601>=0.1.9
-oslotest==1.0
-psutil>=1.1.1
+oslotest
+psutil>=1.1.1,<2.0.0
 netifaces>=0.10.4
diff --git a/setup.py b/setup.py
index 70c2b3f32..736375744 100644
--- a/setup.py
+++ b/setup.py
@@ -17,6 +17,14 @@
 # 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'],
     pbr=True)
diff --git a/test-requirements.txt b/test-requirements.txt
index 08dfe4f42..444d703f7 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -1,4 +1,4 @@
-hacking>=0.8.0,<0.9
+hacking>=0.9.1,<0.10
 coverage>=3.6
 discover
 mock>=1.0