diff --git a/TODO b/TODO
index f84691394c65699447aab3656b978b549c338d99..f0dfa93173bba69c1fb188127394cd769eb4123e 100644
--- a/TODO
+++ b/TODO
@@ -12,6 +12,8 @@ These only run when the goal successfully exits, allowing:
 
  - implicit check_target
 
+Check and enforce there's only a single target per goal.
+
 Multiple definitions of goals:
 
   let goal file_exists filename when filename `starts_with` "/foo" ->