diff --git a/requirements.txt b/requirements.txt
index 025dfac..e540cae 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 python-markdown-math==0.2
 
 alabaster==0.7.8
-Babel==2.3.4
+Babel==2.9.1
 docutils==0.12
 imagesize==0.7.1
 Jinja2>=2.10.1