diff --git a/requirements.txt b/requirements.txt
index bbd9e415..8edf053f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -10,7 +10,7 @@ python-keystoneclient>=3.8.0 # Apache-2.0
 simplejson>=2.2.0 # MIT
 six>=1.9.0 # MIT
 stevedore>=1.20.0 # Apache-2.0
-Babel>=2.3.4 # BSD
+Babel!=2.4.0,>=2.3.4 # BSD
 
 oslo.i18n>=2.1.0 # Apache-2.0
 oslo.log>=3.22.0 # Apache-2.0