diff --git a/requirements.txt b/requirements.txt
index 11822e8..0618270 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,6 +2,6 @@ Markdown==2.6.11
 beautifulsoup4==4.4.1
 cssutils==1.0.1
 inlinestyler==0.2.1
-lxml==3.5
+lxml==4.9.1
 pystache==0.5.4
 parse==1.8.2