diff --git a/requirements.txt b/requirements.txt
index cd1a3ac..451d78f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -69,7 +69,7 @@ jupyter-console==6.1.0
 jupyter-core==4.6.3
 jupyter-plotly-dash==0.4.2
 kiwisolver==1.2.0
-lxml==4.5.0
+lxml==4.9.1
 MarkupSafe==1.1.1
 matplotlib==3.2.1
 mistune==0.8.4