diff --git a/requirements.txt b/requirements.txt
index b9abc2c..2fb9c16 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -56,7 +56,7 @@ lazr.uri==1.0.3
 lazy-object-proxy==1.3.1
 libclang-py3==3.4.0
 louis==3.0.0
-lxml==3.7.3
+lxml==4.9.1
 Mako==1.0.6
 mando==0.3.3
 MarkupSafe==1.0