diff --git a/TODO b/TODO
index 5987c2d..aace6d5 100644
--- a/TODO
+++ b/TODO
@@ -4,3 +4,6 @@ finish implementing --quiet
 
 isync gets confused when new mail is delivered while in the middle of an
 IMAP session.  need to handled those asynchronous notifications properly.
+
+in order to be in total compliance with the maildir(5) spec, we need to
+add code to clean the tmp directory on the 24-hour timer.