diff --git a/requirements.txt b/requirements.txt
index 20a22fe..88e449f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,20 +1,20 @@
 # 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.
-pbr<2.0,>=1.4
+pbr<2.0,>=1.6
 six>=1.9.0
 
 Babel>=1.3
 cliff>=1.14.0 # Apache-2.0
 cliff-tablib>=1.0
 os-client-config!=1.6.2,>=1.4.0
-oslo.config>=2.1.0 # Apache-2.0
+oslo.config>=2.3.0 # Apache-2.0
 oslo.i18n>=1.5.0 # Apache-2.0
 oslo.utils>=2.0.0 # Apache-2.0
 python-glanceclient>=0.18.0
 python-keystoneclient>=1.6.0
-python-novaclient>=2.26.0
+python-novaclient>=2.28.1
 python-cinderclient>=1.3.1
-python-neutronclient<3,>=2.6.0
+python-neutronclient>=2.6.0
 requests>=2.5.2
 stevedore>=1.5.0 # Apache-2.0