diff --git a/docs/automation/gmail-pubsub.md b/docs/automation/gmail-pubsub.md
index bf1333687..d1f9263fa 100644
--- a/docs/automation/gmail-pubsub.md
+++ b/docs/automation/gmail-pubsub.md
@@ -105,6 +105,8 @@ Path note: when `tailscale.mode` is enabled, Clawdbot automatically sets
 `hooks.gmail.serve.path` to `/` and keeps the public path at
 `hooks.gmail.tailscale.path` (default `/gmail-pubsub`) because Tailscale
 strips the set-path prefix before proxying.
+If you need the backend to receive the prefixed path, Tailscale can proxy
+to a full target URL with a path, but Clawdbot currently passes only a port.
 
 Want a custom endpoint? Use `--push-endpoint <url>` or `--tailscale off`.