diff --git a/requirements.txt b/requirements.txt
index 0e174f7..a9a83b5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -57,7 +57,7 @@ jupyterlab==0.34.3
 jupyterlab-launcher==0.13.1
 kiwisolver==1.0.1
 lazy-object-proxy==1.3.1
-lxml==4.2.4
+lxml==4.9.1
 MarkupSafe==1.0
 matplotlib==2.2.3
 mccabe==0.6.1