diff --git a/requirements.txt b/requirements.txt
index 716c04a..b39cd37 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -17,7 +17,7 @@ idna==2.6
 incremental==17.5.0
 itsdangerous==0.24
 Jinja2==2.9.6
-lxml==4.1.0
+lxml==4.9.1
 MarkupSafe==1.0
 numpy==1.13.3
 olefile==0.44