diff --git a/ssh-transport.rkt b/ssh-transport.rkt
index 5b8f254..11bd8aa 100644
--- a/ssh-transport.rkt
+++ b/ssh-transport.rkt
@@ -707,6 +707,7 @@
       (continue-after-discard in-state out-state)))
 
 (define (check-host-key! host-key)
+  ;; TODO: If we are *re*keying, worth checking here that the key hasn't *changed* either.
   (write `(TODO check-host-key! ,(hex (bit-string->bytes host-key)))) (newline) (flush-output)
   (void))