diff --git a/requirements.txt b/requirements.txt
index b5ee15c..9923ee9 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -33,7 +33,7 @@ jupyter==1.0.0
 jupyter-client==5.1.0
 jupyter-console==5.2.0
 jupyter-core==4.3.0
-lxml==4.1.1
+lxml==4.9.1
 Markdown==2.6.8
 MarkupSafe==1.0
 mistune==0.7.4