diff --git a/.changeset/protocol-version-13.md b/.changeset/protocol-version-13.md
new file mode 100644
index 0000000000..096bb751f9
--- /dev/null
+++ b/.changeset/protocol-version-13.md
@@ -0,0 +1,13 @@
+---
+'@objectstack/spec': patch
+---
+
+fix(spec): bump `PROTOCOL_VERSION` to 13.0.0 — restore lockstep with the package major
+
+The ADR-0090 P1 breaking wave took the platform to 13.0.0, but the protocol
+constant (the value the `engines.protocol` handshake compares) stayed at
+12.0.0, tripping the lockstep guard in `protocol-version.test.ts` and turning
+`Test Core` red on main for every PR. Protocol 13 is semantically correct:
+the P1 renames (`roles:` → `positions:`, kind `role`/`profile` → `position`,
+no aliases) are exactly the kind of authorable-surface break the handshake
+exists to refuse across majors.
diff --git a/packages/spec/src/kernel/protocol-version.ts b/packages/spec/src/kernel/protocol-version.ts
index b5d0924ad8..874d60bfdc 100644
--- a/packages/spec/src/kernel/protocol-version.ts
+++ b/packages/spec/src/kernel/protocol-version.ts
@@ -15,7 +15,7 @@
  * Kept in lockstep with the package's own major; `protocol-version.test.ts`
  * asserts it against `package.json` so the two cannot drift.
  */
-export const PROTOCOL_VERSION = '12.0.0';
+export const PROTOCOL_VERSION = '13.0.0';
 
 /** The protocol major as an integer — the value the handshake compares. */
 export const PROTOCOL_MAJOR: number = Number.parseInt(PROTOCOL_VERSION.split('.')[0]!, 10);