diff --git a/package-lock.json b/package-lock.json
index 8179554..47cb542 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "filegrc-monorepo",
-  "version": "0.21.3",
+  "version": "0.21.4",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "filegrc-monorepo",
-      "version": "0.21.3",
+      "version": "0.21.4",
       "workspaces": [
         "packages/filegrc",
         "packages/create-filegrc"
@@ -24,7 +24,7 @@
       "link": true
     },
     "packages/create-filegrc": {
-      "version": "0.21.3",
+      "version": "0.21.4",
       "license": "MIT",
       "bin": {
         "create-filegrc": "bin/create-filegrc.js"
@@ -34,7 +34,7 @@
       }
     },
     "packages/filegrc": {
-      "version": "0.21.3",
+      "version": "0.21.4",
       "license": "MIT",
       "bin": {
         "filegrc": "bin/filegrc.js"
diff --git a/package.json b/package.json
index 10416fd..e84fb64 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "filegrc-monorepo",
-  "version": "0.21.3",
+  "version": "0.21.4",
   "private": true,
   "workspaces": [
     "packages/filegrc",
diff --git a/packages/create-filegrc/package.json b/packages/create-filegrc/package.json
index 4dc04f4..c66be8d 100644
--- a/packages/create-filegrc/package.json
+++ b/packages/create-filegrc/package.json
@@ -1,6 +1,6 @@
 {
   "name": "create-filegrc",
-  "version": "0.21.3",
+  "version": "0.21.4",
   "description": "Create a filegrc workspace for a SOC 2 program",
   "license": "MIT",
   "repository": {
diff --git a/packages/create-filegrc/src/index.js b/packages/create-filegrc/src/index.js
index e57525f..b8913ac 100644
--- a/packages/create-filegrc/src/index.js
+++ b/packages/create-filegrc/src/index.js
@@ -524,13 +524,13 @@ async function runCombinedSetup(target, input) {
 async function writeMinimalLockfile(target, name, versionRange) {
   const lock = {
     name,
-    version: "0.21.3",
+    version: "0.21.4",
     lockfileVersion: 3,
     requires: true,
     packages: {
       "": {
         name,
-        version: "0.21.3",
+        version: "0.21.4",
         dependencies: { filegrc: versionRange }
       }
     }
diff --git a/packages/create-filegrc/template/package.json b/packages/create-filegrc/template/package.json
index 3ff6007..10f62a2 100644
--- a/packages/create-filegrc/template/package.json
+++ b/packages/create-filegrc/template/package.json
@@ -1,6 +1,6 @@
 {
   "name": "{{project_name}}",
-  "version": "0.21.3",
+  "version": "0.21.4",
   "private": true,
   "description": "filegrc workspace for a SOC 2 program",
   "type": "module",
diff --git a/packages/filegrc/package.json b/packages/filegrc/package.json
index 3fdc338..0c73690 100644
--- a/packages/filegrc/package.json
+++ b/packages/filegrc/package.json
@@ -1,6 +1,6 @@
 {
   "name": "filegrc",
-  "version": "0.21.3",
+  "version": "0.21.4",
   "description": "Zero-dependency Git-native GRC engine",
   "license": "MIT",
   "repository": {
diff --git a/packages/filegrc/src/workflow-history-integrity.js b/packages/filegrc/src/workflow-history-integrity.js
index 1a78a84..6a04a71 100644
--- a/packages/filegrc/src/workflow-history-integrity.js
+++ b/packages/filegrc/src/workflow-history-integrity.js
@@ -842,7 +842,7 @@ function canonicalJson(value, field = null, revisionMap = false) {
 async function compareMarkdownAtRevision(loaded, entry, historical, diagnostics, occurrenceId = null) {
   for (const markdown of markdownEntries(loaded.model, entry.record)) {
     const historicalPath = markdownEntries(loaded.model, historical.record)
-      .find(({ slot }) => slot === markdown.slot)?.path;
+      .find(({ name }) => name === markdown.name)?.path;
     const committed = historicalPath
       ? getFileAtRevision(loaded.root, historical.commit, `data/${historicalPath}`)
       : null;
diff --git a/packages/filegrc/test/workflow-proof.test.js b/packages/filegrc/test/workflow-proof.test.js
index 0ca0fef..c5e52a9 100644
--- a/packages/filegrc/test/workflow-proof.test.js
+++ b/packages/filegrc/test/workflow-proof.test.js
@@ -5,6 +5,8 @@ import { join } from "node:path";
 import test from "node:test";
 import { loadWorkspace, updateResource, validateWorkspace } from "../src/index.js";
 import { validateWorkflowHistoryIntegrity } from "../src/workflow-history-integrity.js";
+import { markdownEntries } from "../src/resource-markdown.js";
+import { loadModel, SUPPORTED_MODEL_VERSIONS } from "../model/index.js";
 import { workflowProofIds } from "../src/workflow-proof.js";
 import { makeComprehensiveWorkspace } from "./fixtures.js";
 import { commitWorkspaceFiles, initializeGitWorkspace, writeJson } from "./helpers.js";
@@ -68,9 +70,87 @@ test("mutable source context evolves while finalized proof stays bound to Git",
   await writeJson(evidence.path, { ...evidence.record, sourceResourceIds: [] });
   assert.ok((await historyDiagnostics()).some(({ message }) => message.includes(`Proof record "${evidence.record.id}" differs`)));
   await writeJson(evidence.path, evidence.record);
+  const companion = markdownEntries(loaded.model, completion.record)[0];
+  const companionPath = join(root, "data", companion.path);
+  const originalCompanion = await readFile(companionPath, "utf8").catch(() => null);
+  await writeFile(companionPath, "# Changed single-slot proof\n");
+  assert.ok((await historyDiagnostics()).some(({ code, path }) => code === "rewritten-finalized-content" && path === `data/${companion.path}`));
+  if (originalCompanion === null) await rm(companionPath);
+  else await writeFile(companionPath, originalCompanion);
   const attachment = evidence.record.filePaths?.[0];
   assert.ok(attachment);
   const original = await readFile(join(root, "data", attachment));
   await writeFile(join(root, "data", attachment), Buffer.concat([original, Buffer.from("rewritten")]));
   assert.ok((await historyDiagnostics()).some(({ message }) => /attachment/i.test(message)));
 });
+
+
+test("supported models identify every meeting companion by name", () => {
+  for (const version of SUPPORTED_MODEL_VERSIONS) {
+    const model = loadModel(version);
+    const multiSlotTypes = Object.entries(model.resources)
+      .filter(([, definition]) => Object.keys(definition.markdown || {}).length > 1)
+      .map(([type]) => type);
+    assert.deepEqual(multiSlotTypes, ["meeting"], `model v${version}`);
+    const entries = markdownEntries(model, { type: "meeting", id: "meeting-example" });
+    assert.deepEqual(entries.map(({ name }) => name), ["agenda", "minutes"]);
+    assert.equal(entries.find(({ primary }) => primary).name, "minutes");
+    assert.match(entries[0].path, /-agenda\.md$/);
+    assert.match(entries[1].path, /meeting-example\.md$/);
+  }
+});
+
+for (const { version, extended = false } of [{ version: "9" }, { version: "13" }, { version: "13", extended: true }]) {
+  test(`committed meeting proof preserves each Markdown companion in model v${version}${extended ? " with extended slots" : ""}`, async (t) => {
+    const root = await mkdtemp(join(tmpdir(), "filegrc-meeting-proof-"));
+    t.after(() => rm(root, { recursive: true, force: true }));
+    await makeComprehensiveWorkspace(root, version);
+    const extendModel = (loaded) => {
+      if (extended) loaded.model.resources.meeting.markdown = {
+        followUpPath: { label: "Follow-up", primary: true },
+        minutes: { label: "Minutes" },
+        agenda: { label: "Agenda" }
+      };
+      return loaded;
+    };
+    const loaded = extendModel(await loadWorkspace(root));
+    const meeting = loaded.entries.find(({ record }) => record.type === "meeting");
+    const occurrence = loaded.entries.find(({ record }) => record.type === "obligation-occurrence");
+    const obligation = loaded.entries.find(({ record }) => record.type === "obligation");
+    obligation.record.activityType = "meeting";
+    await writeJson(obligation.path, obligation.record);
+    occurrence.record.members[0].resourceId = loaded.workspace.id;
+    occurrence.record.members[0].completionResourceIds = [meeting.record.id];
+    await writeJson(occurrence.path, occurrence.record);
+    const companions = markdownEntries(loaded.model, meeting.record);
+    const originals = new Map(companions.map(({ path, name }) => [path, `# ${name}\nDistinct ${name} proof.\n`]));
+    for (const [path, content] of originals) await writeFile(join(root, "data", path), content);
+    await initializeGitWorkspace(root, { message: "Finalize meeting and occurrence with distinct companions" });
+    const diagnostics = async () => {
+      const result = [];
+      await validateWorkflowHistoryIntegrity(extendModel(await loadWorkspace(root)), result);
+      return result;
+    };
+    assert.deepEqual(await diagnostics(), []);
+    if (version === "9") assert.deepEqual((await validateWorkspace(root)).diagnostics, []);
+    for (const { path } of companions) {
+      const absolute = join(root, "data", path);
+      await writeFile(absolute, "# Changed proof\n");
+      assert.ok((await diagnostics()).some((item) => item.code === "rewritten-finalized-content" && item.path === `data/${path}`));
+      await writeFile(absolute, originals.get(path));
+      await rm(absolute);
+      assert.ok((await diagnostics()).some((item) => item.code === "rewritten-finalized-content" && item.path === `data/${path}`));
+      await writeFile(absolute, originals.get(path));
+    }
+    assert.deepEqual(await diagnostics(), []);
+    // An optional companion absent at finalization cannot be added afterward.
+    const agenda = companions.find(({ name }) => name === "agenda");
+    await rm(join(root, "data", agenda.path));
+    // Start a separate history so the absence is part of the first final version.
+    await rm(join(root, ".git"), { recursive: true, force: true });
+    await initializeGitWorkspace(root, { message: "Finalize meeting without optional agenda" });
+    assert.deepEqual(await diagnostics(), []);
+    await writeFile(join(root, "data", agenda.path), originals.get(agenda.path));
+    assert.ok((await diagnostics()).some((item) => item.code === "rewritten-finalized-content" && item.path === `data/${agenda.path}`));
+  });
+}