diff --git a/design-notes/todo.md b/design-notes/todo.md
index 445f462be..617f97bd8 100644
--- a/design-notes/todo.md
+++ b/design-notes/todo.md
@@ -33,3 +33,4 @@
 ## TreeSelect
 
 - (moderate) Async
+- (easy) Leaf-only check