diff --git a/requirements.txt b/requirements.txt
index 03e722e..c2b82cf 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -20,7 +20,7 @@ idna==2.6
 ipaddress==1.0.18
 itypes==1.1.0
 Jinja2==2.10
-lxml==4.1.1
+lxml==4.9.1
 MarkupSafe==1.0
 mongoengine==0.9.0
 numpy==1.13.1