diff --git a/requirements.txt b/requirements.txt
index ae5b4ef..7606855 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,7 +2,7 @@ Flask==1.0.2
 Flask-SQLAlchemy==2.0
 itsdangerous==0.24
 Jinja2==2.7.3
-lxml==3.4.4
+lxml==4.9.1
 Markdown==2.6.2
 MarkupSafe==0.23
 pyyaml>=4.2b1