diff --git a/TODO.md b/TODO.md
index 1e2eeab..e86b00f 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1748,3 +1748,19 @@ this library and told it is compatible.
    `akgl_character_state_sprites_iterate` is still uncovered and is the natural
    place to start; `tests/actor.c` now covers `akgl_character_sprite_get` and the
    composite-state binding behavior it depends on.
+
+2. **An actor cannot be scaled per axis.** `akgl_Actor::scale` is one `float32_t` applied
+   to both `dest.w` and `dest.h`, so there is no way to express "twice as wide, the same
+   height". The VIC-II has had separate x- and y-expand bits since 1982 and Commodore
+   BASIC 7.0's `SPRITE` verb exposes both, so a BASIC interpreter drawing through libakgl
+   cannot implement its own documented verb.
+
+   Two shapes are plausible and the choice is a design decision rather than an obvious
+   fix: add `scale_x` / `scale_y` and keep `scale` as a convenience that writes both, or
+   replace `scale` outright and take the ABI break while the major version is still 0.
+   The second is cleaner and the soname already carries `MAJOR.MINOR`.
+
+   Related to defect 26, and reached the same way: `akbasic`'s sprites are Commodore
+   sprites, 24 wide and 21 high, and `SPRITE n,,,,1` expands one axis. It works around
+   both by installing its own `renderfunc` on each actor rather than patching around the
+   library.