diff --git a/docs/requirements.txt b/docs/requirements.txt
index 4b7638d..bd14e4a 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -4,7 +4,7 @@ Jinja2==2.10.1
 MarkupSafe==1.1.1
 Pygments==2.2.0
 alabaster==0.7.10
-babel==2.4.0
+babel==2.9.1
 gitdb==0.6.4
 imagesize==0.7.1
 pytz==2017.2