diff --git a/requirements.txt b/requirements.txt
index 991c368..7acf1b0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,5 +2,5 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-pbr>=2.0.0 # Apache-2.0
-Babel>=2.3.4 # BSD
+pbr!=2.1.0,>=2.0.0 # Apache-2.0
+Babel!=2.4.0,>=2.3.4 # BSD
diff --git a/test-requirements.txt b/test-requirements.txt
index 60d03cb..b773920 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -4,9 +4,9 @@
 
 hacking!=0.13.0,<0.14,>=0.12.0 # Apache-2.0
 
-coverage>=4.0 # Apache-2.0
+coverage!=4.4,>=4.0 # Apache-2.0
 python-subunit>=0.0.18 # Apache-2.0/BSD
-sphinx>=1.5.1 # BSD
+sphinx!=1.6.1,>=1.5.1 # BSD
 psycopg2>=2.5 # LGPL/ZPL
 PyMySQL>=0.7.6 # MIT License
 oslosphinx>=4.7.0 # Apache-2.0