diff --git a/requirements.txt b/requirements.txt
index 21ca2a14..857382ac 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,4 +4,4 @@ pep8==1.4.5
 pyflakes>=0.7.2,<0.7.4
 flake8==2.0
 
-six<1.4.0
+six
diff --git a/setup.py b/setup.py
index 2a0786a8..70c2b3f3 100755
--- a/setup.py
+++ b/setup.py
@@ -18,5 +18,5 @@
 import setuptools
 
 setuptools.setup(
-    setup_requires=['pbr>=0.5.21,<1.0'],
+    setup_requires=['pbr'],
     pbr=True)