diff --git a/requirements.txt b/requirements.txt
index 2e08d4c..c6a4fd1 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 requests==2.20.0
-lxml==4.6.3
+lxml==4.9.1
 beautifulsoup4==4.4.1
 six==1.10.0
 Flask-Sphinx-Themes==1.0.1
\ No newline at end of file