diff --git a/requirements.txt b/requirements.txt
index 10c4ffd..152cee0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -29,7 +29,7 @@ Jinja2==2.8
 kiwisolver==1.0.1
 language-selector==0.1
 louis==2.6.4
-lxml==3.5.0
+lxml==4.9.1
 Mako==1.0.3
 MarkupSafe==0.23
 matplotlib==3.0.2