diff --git a/pantheon.upstream.yml b/pantheon.upstream.yml
index 67c3dd1..258171e 100644
--- a/pantheon.upstream.yml
+++ b/pantheon.upstream.yml
@@ -1,5 +1,17 @@
+# IMPORTANT NOTE:
+# Do not edit this file unless you are doing so in your custom upstream repository.
+# Override the defaults specified here in a site-specific `pantheon.yml` file.
+# For more information see: https://pantheon.io/docs/pantheon-upstream-yml
 api_version: 1
 web_docroot: true
-php_version: 7.3
+php_version: 7.4
 build_step: true
 
+# See https://pantheon.io/docs/pantheon-yml#specify-a-version-of-mariadb
+database:
+  version: 10.4
+
+# See https://pantheon.io/docs/pantheon-yml/#enforce-https--hsts for valid values.
+enforce_https: transitional
+
+