diff --git a/requirements.txt b/requirements.txt
index 84c55f0..22c9492 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -25,7 +25,7 @@ jupyter==1.0.0
 jupyter-client==5.2.2
 jupyter-console==5.2.0
 jupyter-core==4.4.0
-lxml==4.1.1
+lxml==4.9.1
 MarkupSafe==1.0
 mistune==0.8.3
 nbconvert==5.3.1