diff --git a/docs/UPGRADE.md b/docs/UPGRADE.md
index cbd940e6..8df21b4c 100644
--- a/docs/UPGRADE.md
+++ b/docs/UPGRADE.md
@@ -22,6 +22,7 @@ After:
 
 ```caddyfile
 transport bolt {
+  path mercure.db
   cleanup_frequency 0.2
 }
 ```