diff --git a/unicode-todo.txt b/unicode-todo.txt
index 7aa3966da65..cd2d133a231 100644
--- a/unicode-todo.txt
+++ b/unicode-todo.txt
@@ -55,5 +55,5 @@
 * Change implementation of strtoupper()/strtolower() to use simple case
   mapping.
 
-* Store script encoding in the oparray structure and use it to convert
-  T_INLINE_HTML blocks.
+* Optimize T_INLINE_HTML blocks conversion by either creating a converter
+  cache or remembering the last used converter in the executor globals.