diff --git a/requirements.txt b/requirements.txt
index d5e5762..0a67cca 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,7 +4,7 @@ pymongo==3.8.0
 numpy==1.17.0
 Werkzeug==0.15.3
 Jinja2==2.10
-lxml==4.3.4
+lxml==4.9.1
 pycryptodome==3.9.4
 Cython==0.29.14
 pyOpenSSL==19.1.0