diff --git a/requirements.txt b/requirements.txt
index cad7640..f9980ad 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -24,7 +24,7 @@ jupyter-client==5.2.3
 jupyter-console==5.2.0
 jupyter-core==4.4.0
 kiwisolver==1.0.1
-lxml==4.2.1
+lxml==4.9.1
 MarkupSafe==1.0
 matplotlib==2.2.2
 mistune==0.8.3