diff --git a/requirements.txt b/requirements.txt
index 34515ef..ac5e59d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -28,7 +28,7 @@ itsdangerous==0.24
 Jinja2==2.9.1
 liblarch==2.1.0
 lockfile==0.8
-lxml==3.3.3
+lxml==4.6.5
 Mako==0.9.1
 MarkupSafe==0.23
 matplotlib==1.3.1