diff --git a/requirements.txt b/requirements.txt
index c76ba29..4267dc6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,7 +7,7 @@ Jinja2==2.7.3
 python-slugify
 django-debug-toolbar==1.4
 markupsafe
-lxml==3.4.4
+lxml==4.9.1
 graphviz==0.4.9
 ncclient==0.5.2
 pyang==1.6.0