diff --git a/FABRIC.md b/FABRIC.md
index d3cb469..e2d9320 100644
--- a/FABRIC.md
+++ b/FABRIC.md
@@ -2089,10 +2089,18 @@ document and committing that amendment as its own item.*
 - [ ] **2.1 — Restate heat transfer on tick count.**
   `vm_physics_touch()` scales transfers by wall-clock elapsed time
   (`capsule_vm_physics.c:272`). Restate it on tick count.
-  *Done when:* no wall-clock value influences heat, and the double-boot reproducibility
-  check from 0.10 still passes.
+  *Done when:* no wall-clock value influences heat, **and the same capsule booted twice
+  produces an identical fleet heat sum across the two runs.**
   *Refs:* §18.5, §19.6 #3.
 
+  > **Acceptance corrected.** This item previously accepted on the dictionary-hash
+  > double-boot check from 0.10. That cannot detect this work: §18.5 establishes that
+  > `vm_physics_touch()` writes `node->physics`, **not** `DictEntry.execution_heat`, and
+  > therefore never reaches the parity hash. The dict hash would be identical whether 2.1
+  > succeeded, failed, or was skipped. Fleet heat is the quantity this item changes, so
+  > fleet heat is what has to be compared. Run 0.10's dict-hash check as well, as a
+  > regression guard — but it is not evidence for 2.1.
+
 - [ ] **2.2 — Bound the VM registry.**
   The registry is a `kmalloc`-backed unbounded list, which makes fleet K an identity that
   cannot fail (§20.2). Give it the hard bound decided in 1.5.