diff --git a/requirements.txt b/requirements.txt
index c401ee6..1b6fe1c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,6 @@
 alabaster==0.7.10
 appnope==0.1.0
-Babel==2.4.0
+Babel==2.9.1
 certifi==2017.4.17
 chardet==3.0.4
 CommonMark==0.5.4