diff --git a/requirements.txt b/requirements.txt
index ac211e2..e1b09b2 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -23,7 +23,7 @@ jupyter==1.0.0
 jupyter-client==5.3.4
 jupyter-console==6.0.0
 jupyter-core==4.6.1
-lxml==4.4.2
+lxml==4.9.1
 MarkupSafe==1.1.1
 mistune==0.8.4
 more-itertools==8.0.2