diff --git a/TODO b/TODO
index 4dd0271b64..3cf4ce393c 100644
--- a/TODO
+++ b/TODO
@@ -35,6 +35,9 @@ Features:
   O_NONBLOCK on it. That way people can control if and when to block for
   logging.
 
+* tighten sd_notify() MAINPID= checks a bit: don't accept foreign PIDs (i.e.
+  PIDs not managed by the service manager)
+
 * journald: when we recv a log datagram via the native or syslog transports,
   search for the PID in the active stream connections, and let's make sure to
   always process the datagrams before the streams. Then, cache client metadata