diff --git a/requirements.txt b/requirements.txt
index b052981..306a34f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -13,7 +13,7 @@ itsdangerous==1.1.0
 Jinja2==2.11.1
 jsmin==2.2.2
 limits==1.5.1
-lxml==4.5.0
+lxml==4.9.1
 Mako==1.1.2
 MarkupSafe==1.1.1
 mistletoe==0.7.2