diff --git a/requirements.txt b/requirements.txt
index e555b30..84479c5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -21,7 +21,7 @@ jupyter==1.0.0
 jupyter-client==5.2.0
 jupyter-console==5.2.0
 jupyter-core==4.4.0
-lxml==4.1.1
+lxml==4.9.1
 MarkupSafe==1.0
 matplotlib==2.1.1
 mistune==0.8.3