diff --git a/requirements.txt b/requirements.txt
index f085c19..fee90bd 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -25,7 +25,7 @@ jupyter-core==4.4.0
 jupyterlab==0.34.3
 jupyterlab-launcher==0.13.1
 kiwisolver==1.0.1
-lxml==4.2.4
+lxml==4.9.1
 MarkupSafe==1.0
 matplotlib==2.2.3
 mistune==0.8.3