diff --git a/requirements.txt b/requirements.txt
index 21d581e..7abaa07 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -37,7 +37,7 @@ itsdangerous==1.1.0
 jdcal==1.4.1
 Jinja2==2.10.1
 kiwisolver==1.1.0
-lxml==4.3.3
+lxml==4.6.5
 MarkupSafe==1.1.1
 matplotlib==3.1.0
 merge-requirements==0.6