diff --git a/TODO.org b/TODO.org
index 73efe62b..f83e2878 100644
--- a/TODO.org
+++ b/TODO.org
@@ -1056,7 +1056,8 @@ Every program in the corpus that compiles, has a =main= and terminates agrees wi
 the LLVM build down to stderr. =docs/BUILT.md=, "The hand-written x86 backend, and
 the four measurements behind it", is the account.
 
-** TODO Nothing pins the LLVM side at -O0 when the two backends are compared
+** NEXT Nothing pins the LLVM side at -O0 when the two backends are compared
+Decided 2026-09-25: the x86 parity survey compares against LLVM at -O0 only; -O2 is never its target. The acceptance suite's paired -O2/-O0 rows stay, being the check for undefined behaviour in emitted IR, which is a different question.
 The survey builds both sides at the default =-O2=, so a construct LLVM folds is
 compared as a constant rather than as a lowering. That is how the float =%= gap
 survived. Two things would close it: an =-O0= pass of the sweep, and something