diff --git a/todo.txt b/todo.txt
index 03447b2..cf3e353 100644
--- a/todo.txt
+++ b/todo.txt
@@ -1,2 +1,3 @@
 - onHeader, etc callbacks for Matroska
-- https://github.com/Vanilagy/mp4-muxer/issues/83 tell him it's possible now
\ No newline at end of file
+- https://github.com/Vanilagy/mp4-muxer/issues/83 tell him it's possible now
+- is this fixed? https://github.com/Vanilagy/webm-muxer/issues/50
\ No newline at end of file