diff --git a/TODO.org b/TODO.org
index f0c1f584..542a1ca8 100644
--- a/TODO.org
+++ b/TODO.org
@@ -737,10 +737,12 @@ call site that asked for that type. The data is there — =instantiation_origin=
 exists and the session already uses it — and wiring it into every failure under an
 instantiation is a lane of its own.
 
-** TODO Generics across a real compilation-unit boundary
-It works today because =Load= flattens imports before checking. A package boundary
-that ever becomes a real unit boundary needs the generic's body to cross it, which
-separate compilation cannot do — which is why C++ puts templates in headers.
+** DONE A program is one compilation, so a generic's body is always visible
+CLOSED: [2026-09-25]
+Odin's and Zig's model: packages are never compiled separately. The cost is build
+time proportional to the whole program and no binary-only packages. If separate
+compilation is ever wanted, Rust's answer is the one to take — a compiled package
+carries its generics' checked bodies and the user instantiates them.
 
 ** DONE Collapsing the prelude buys 27 to 15, not 27 to 6
 CLOSED: [2026-09-13]