diff --git a/requirements.txt b/requirements.txt
index 59f3251f4..7a8bbdc0b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,7 +3,7 @@
 # process, which may cause wedges in the gate later.
 automaton>=0.5.0 # Apache-2.0
 alembic>=0.8.10 # MIT
-Babel>=2.3.4 # BSD
+Babel!=2.4.0,>=2.3.4 # BSD
 construct>=2.8.10 # MIT
 eventlet!=0.18.3,>=0.18.2 # MIT
 Flask!=0.11,<1.0,>=0.10 # BSD