diff --git a/docs/requirements.txt b/docs/requirements.txt
index b371094..6c44c35 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -82,7 +82,7 @@ kostal-ardexa==0.2.1
 lanscan==0.9.5
 lazy-object-proxy==1.3.1
 libusb1==1.7
-lxml==4.2.1
+lxml==4.9.1
 m2r==0.2.1
 macholib==1.9
 mapsplotlib==1.1.1