diff --git a/requirements_python36.txt b/requirements_python36.txt
index a4de280..b2a7303 100644
--- a/requirements_python36.txt
+++ b/requirements_python36.txt
@@ -64,7 +64,7 @@ kitti2bag==1.5
 language-selector==0.1
 laser-geometry==1.6.4
 louis==2.6.4
-lxml==3.5.0
+lxml==4.9.1
 Mako==1.0.3
 MarkupSafe==1.0
 matplotlib==2.1.2