diff --git a/examples/heroku/requirements.txt b/examples/heroku/requirements.txt
index 24cc3e223..f5fa6f945 100644
--- a/examples/heroku/requirements.txt
+++ b/examples/heroku/requirements.txt
@@ -1,3 +1,5 @@
 slack_bolt
-Flask>=1.1
-gunicorn>=20
\ No newline at end of file
+Flask>=2.2.5
+gunicorn>=20
+jinja2>=3.1.4 # not directly required, pinned by Snyk to avoid a vulnerability
+werkzeug>=2.2.3 # not directly required, pinned by Snyk to avoid a vulnerability
\ No newline at end of file