diff --git a/requirements.txt b/requirements.txt
index a20e669..6168be7 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -87,7 +87,7 @@ jupyterlab-launcher==0.10.2
 lazy-object-proxy==1.3.1
 llvmlite==0.21.0
 locket==0.2.0
-lxml==4.1.1
+lxml==4.9.1
 MarkupSafe==1.0
 matplotlib==2.1.2
 mccabe==0.6.1