diff --git a/requirements.txt b/requirements.txt
index f9bae0543e..a1bb8b1fc3 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,7 +4,7 @@
 pbr>=2.0.0 # Apache-2.0
 six>=1.9.0 # MIT
 
-Babel>=2.3.4 # BSD
+Babel!=2.4.0,>=2.3.4 # BSD
 cliff>=2.3.0 # Apache-2.0
 keystoneauth1>=2.18.0 # Apache-2.0
 openstacksdk>=0.9.14 # Apache-2.0