diff --git a/todo.txt b/todo.txt
index b2350ab5c..3e5bc52b0 100644
--- a/todo.txt
+++ b/todo.txt
@@ -25,6 +25,8 @@ TODO, which will get actually done
 
 - SDL: new commandline arguments editor adds extra blank parameter at the beginning.
 
+- SDL: support for mounting OBB files as directories: https://developer.android.com/google/play/expansion-files.html
+
 - Debian: proot crashes on Shield TV arm64 box.
 
 - Debian: add harldink simulation to proot, for Android 6.