diff --git a/requirements.txt b/requirements.txt
index e5c3a81..ce8d96f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -17,7 +17,7 @@ isodate==0.6.0
 jedi==0.18.0
 Jinja2==3.0.1
 kiwisolver==1.3.2
-lxml==4.6.5
+lxml==4.9.1
 MarkupSafe==2.0.1
 matplotlib==3.4.3
 matplotlib-inline==0.1.3