diff --git a/todo.txt b/todo.txt
index 3f5dfc6..43ab60d 100644
--- a/todo.txt
+++ b/todo.txt
@@ -1,4 +1,5 @@
 - https://github.com/Vanilagy/mp4-muxer/issues/83 tell him it's possible now
 - cross-track offset for streaming sources
 - textsubtitlesource, chunked piping
-- More efficient MP3 loading when reading sequentially
\ No newline at end of file
+- More efficient MP3 loading when reading sequentially
+- Validate types returned by custom coders
\ No newline at end of file