diff --git a/requirements.txt b/requirements.txt
index 6587cd5..dfb6231 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -24,7 +24,7 @@ jupyter-highlight-selected-word==0.2.0
 jupyter-latex-envs==1.4.6
 jupyter-nbextensions-configurator==0.4.1
 kiwisolver==1.1.0
-lxml==4.5.0
+lxml==4.9.1
 MarkupSafe==1.1.1
 matplotlib==3.1.3
 mistune==0.8.4