diff --git a/appengine/mailer/requirements.txt b/appengine/mailer/requirements.txt
index 97b639a..254a74e 100644
--- a/appengine/mailer/requirements.txt
+++ b/appengine/mailer/requirements.txt
@@ -2,7 +2,7 @@ attrs==19.1.0
 Click==7.0
 Flask==1.1.1
 itsdangerous==1.1.0
-Jinja2==2.10.1
+Jinja2==3.1.3
 MarkupSafe==1.1.1
 pytz==2019.2
 Werkzeug==0.15.6