diff --git a/README.multi-tty b/README.multi-tty
index 8a578937aaf..1e698f3eb82 100644
--- a/README.multi-tty
+++ b/README.multi-tty
@@ -374,6 +374,8 @@ THINGS TO DO
 
 ** Have a look at fatal_error_hook.
 
+** Have a look at set_frame_matrix_frame.
+
 ** Check if we got term-setup-hook right.
 
 ** I think tip_frame should be display-local.