diff --git a/requirements.txt b/requirements.txt
index bac6f40..277cea4 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,7 +2,7 @@ certifi==2020.4.5.1
 chardet==3.0.4
 hupper==1.10.2
 idna==2.9
-lxml==4.5.0
+lxml==4.9.1
 PasteDeploy==2.1.0
 plaster==1.0
 plaster-pastedeploy==0.7