diff --git a/TODO.md b/TODO.md
index bf11acbdb..62868d8ce 100644
--- a/TODO.md
+++ b/TODO.md
@@ -3,7 +3,6 @@
 # After mruby 3.1
 
 - parser and code generator independent from `mrb_state` (picoruby?)
-- variable sized AST node
 - iv/hash entry cache
 - more peephole optimization (if possible)