diff --git a/requirements.txt b/requirements.txt
index 6be0299..7ed638d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -20,7 +20,7 @@ jupyter-core==4.3.0
 jupyter-highlight-selected-word==0.0.11
 jupyter-latex-envs==1.3.8.4
 jupyter-nbextensions-configurator==0.2.8
-lxml==4.6.2
+lxml==4.9.1
 MarkupSafe==1.0
 mistune==0.8.1
 nbconvert==5.3.1