diff --git a/requirements.txt b/requirements.txt
index 34c3737..54d342c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,7 +8,7 @@ idna==2.8
 itsdangerous==1.1.0
 Jinja2==2.10.1
 kiwisolver==1.0.1
-lxml==4.3.3
+lxml==4.6.3
 MarkupSafe==1.1.1
 matplotlib==3.0.3
 numpy==1.16.0