diff --git a/requirements.txt b/requirements.txt
index 6b687db..5ac1288 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 cycler==0.10.0
 decorator==4.4.0
 kiwisolver==1.1.0
-lxml==4.4.1
+lxml==4.9.1
 matplotlib==3.1.1
 networkx==2.3
 numpy==1.17.0