diff --git a/requirements.txt b/requirements.txt
index 9d80603..41c143e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -28,7 +28,7 @@ ipywidgets==6.0.0
 Jinja2==2.9.6
 joblib==0.8.4
 jsonschema==2.6.0
-lxml==3.8.0
+lxml==4.9.1
 MarkupSafe==1.0
 mistune==0.7.4
 mock==2.0.0