diff --git a/requirements.txt b/requirements.txt
index 56502e4..9b2fcb6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,7 +6,7 @@ Flask==1.0.2
 idna==2.8
 itsdangerous==1.1.0
 Jinja2==2.10.1
-lxml==4.3.3
+lxml==4.9.1
 MarkupSafe==1.1.1
 numpy==1.16.2
 packaging==19.0