diff --git a/requirements.txt b/requirements.txt
index 813be82..cde0845 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -19,7 +19,7 @@ Jinja2>=2.10.1
 jsonschema==3.0.1
 jupyter-core==4.4.0
 kiwisolver==1.0.1
-lxml==4.3.2
+lxml==4.9.1
 MarkupSafe==1.1.1
 matplotlib==3.0.3
 nbformat==4.4.0