diff --git a/requirements.txt b/requirements.txt
index 9431e97..f13b373 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 alabaster==0.7.10
-Babel==2.5.3
+Babel==2.9.1
 certifi==2018.1.18
 chardet==3.0.4
 docutils==0.14