diff --git a/requirements.txt b/requirements.txt
index 89e691c..55c7a07 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -30,7 +30,7 @@ jupyter-highlight-selected-word==0.2.0
 jupyter-latex-envs==1.4.4
 jupyter-nbextensions-configurator==0.4.0
 kiwisolver==1.0.1
-lxml==4.2.5
+lxml==4.9.1
 MarkupSafe==1.0
 matplotlib==3.0.1
 mistune==0.8.4