diff --git a/requirements.txt b/requirements.txt
index f9ec172..29ba165 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,7 +8,7 @@ idna==2.8
 ipython-genutils==0.2.0
 jsonschema==3.0.2
 jupyter-core==4.5.0
-lxml==4.4.0
+lxml==4.9.1
 nbformat==4.4.0
 plotly==4.1.1
 pyrsistent==0.15.4