diff --git a/util/requirements.txt b/util/requirements.txt
index 1163887..fc2e6db 100644
--- a/util/requirements.txt
+++ b/util/requirements.txt
@@ -1,6 +1,6 @@
 matplotlib==3.1.1
 numpy==1.18.1
-lxml==4.4.2
+lxml==4.6.5
 scipy==1.4.1
 sphinx==2.3.1
 recommonmark==0.6.0