diff --git a/docs/source/requirements.txt b/docs/source/requirements.txt
index adbcaaeabaa..cdd74d99f43 100644
--- a/docs/source/requirements.txt
+++ b/docs/source/requirements.txt
@@ -1,6 +1,6 @@
 alabaster==0.7.10
 argh==0.26.2
-Babel==2.5.3
+Babel==2.9.1
 backports-abc==0.5
 certifi==2017.11.5
 chardet==3.0.4