diff --git a/requirements.txt b/requirements.txt
index e121be0..8b2a22d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -15,7 +15,7 @@ idna==2.8
 itsdangerous==1.1.0
 Jinja2==2.10
 jws==0.1.3
-lxml==4.3.1
+lxml==4.9.1
 MarkupSafe==1.1.0
 oauth2client==3.0.0
 Pillow==5.4.1