diff --git a/requirements.txt b/requirements.txt
index 6871057..126a3dc 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,10 +2,10 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 hacking!=0.13.0,<0.14,>=0.12.0 # Apache-2.0
-pbr>=1.8 # Apache-2.0
-urllib3>=1.15.1 # MIT
-oslo.log>=3.11.0 # Apache-2.0
-oslo.config>=3.22.0  # Apache-2.0
-oslo.policy>=1.17.0  # Apache-2.0
-tempest>=14.0.0  # Apache-2.0
-stevedore>=1.20.0  # Apache-2.0
+pbr!=2.1.0,>=2.0.0 # Apache-2.0
+urllib3>=1.21.1 # MIT
+oslo.log>=3.22.0 # Apache-2.0
+oslo.config!=4.3.0,!=4.4.0,>=4.0.0 # Apache-2.0
+oslo.policy>=1.23.0 # Apache-2.0
+tempest>=14.0.0 # Apache-2.0
+stevedore>=1.20.0 # Apache-2.0