diff --git a/requirements.txt b/requirements.txt
index d99e42e..d84aee3 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -62,7 +62,7 @@ kiwisolver==1.1.0
 lazy-object-proxy==1.4.3
 llvmlite==0.31.0
 locket==0.2.0
-lxml==4.5.0
+lxml==4.9.1
 Markdown==3.2.1
 MarkupSafe==1.1.1
 matplotlib==3.1.3