diff --git a/lib/__tests__/shared-store-import-auth.test.ts b/lib/__tests__/shared-store-import-auth.test.ts
new file mode 100644
index 000000000..e8f6a7a9a
--- /dev/null
+++ b/lib/__tests__/shared-store-import-auth.test.ts
@@ -0,0 +1,76 @@
+// @vitest-environment node
+import { mkdtempSync, readFileSync, rmSync, writeFileSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import path from 'node:path';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+vi.mock('@/lib/logger', () => ({
+  logger: { warn: vi.fn(), info: vi.fn(), error: vi.fn(), debug: vi.fn() },
+}));
+
+import { setStoreForTests } from '@/lib/shared-store';
+import { resetLocalStoreForTests } from '@/lib/shared-store/local';
+import { steps } from '@/lib/shared-store/import/auth';
+import { limitsEnforcedSince, resetLimitsEnforcedSince } from '@/lib/auth/session-age';
+import { WOPI_TOKEN_TTL_MS, type WopiTokenPayload } from '@/lib/wopi/token';
+import { isWopiTokenRevoked } from '@/lib/wopi/revocation';
+import { switchableSharedStore } from './helpers/shared-store-down';
+
+// Moving a single instance to the shared store (#1066) must carry over the
+// auth state that outlives a restart, and never touch the local files.
+
+let stateDir: string;
+let sharedDir: string;
+
+const run = async () => {
+  const counts: Record<string, number> = {};
+  for (const step of steps) counts[step.name] = await step.run();
+  return counts;
+};
+
+beforeEach(() => {
+  stateDir = mkdtempSync(path.join(tmpdir(), 'bw-import-auth-'));
+  sharedDir = mkdtempSync(path.join(tmpdir(), 'bw-import-store-'));
+  vi.stubEnv('ADMIN_STATE_DIR', stateDir);
+  resetLocalStoreForTests();
+  resetLimitsEnforcedSince();
+  delete (globalThis as Record<symbol, unknown>)[Symbol.for('bulwark.wopiRevocations')];
+  setStoreForTests(switchableSharedStore({ sharedDir }));
+});
+
+afterEach(() => {
+  setStoreForTests(null);
+  resetLocalStoreForTests();
+  resetLimitsEnforcedSince();
+  vi.unstubAllEnvs();
+  rmSync(stateDir, { recursive: true, force: true });
+  rmSync(sharedDir, { recursive: true, force: true });
+});
+
+describe('import steps of the auth stores', () => {
+  it('copies session-limits-since and the WOPI revocations once, leaving the local files alone', async () => {
+    const revokedAt = Date.now() - 60_000;
+    writeFileSync(path.join(stateDir, 'session-limits-since'), '1700000000000');
+    writeFileSync(path.join(stateDir, 'wopi-revocations.json'), JSON.stringify({ 'browser-a:0': revokedAt }));
+    const before = [
+      readFileSync(path.join(stateDir, 'session-limits-since')),
+      readFileSync(path.join(stateDir, 'wopi-revocations.json')),
+    ];
+
+    expect(await run()).toEqual({ 'session-limits-since': 1, 'wopi-revocations': 1 });
+    expect(await run()).toEqual({ 'session-limits-since': 0, 'wopi-revocations': 0 });
+
+    expect(readFileSync(path.join(stateDir, 'session-limits-since'))).toEqual(before[0]);
+    expect(readFileSync(path.join(stateDir, 'wopi-revocations.json'))).toEqual(before[1]);
+
+    // What the replicas now read comes from the store, not the old volume.
+    rmSync(stateDir, { recursive: true, force: true });
+    expect(await limitsEnforcedSince()).toBe(1_700_000_000_000);
+    const payload = { bid: 'browser-a', slot: 0, exp: revokedAt - 1000 + WOPI_TOKEN_TTL_MS } as WopiTokenPayload;
+    expect(await isWopiTokenRevoked(payload)).toBe(true);
+  });
+
+  it('writes nothing for an install that has neither', async () => {
+    expect(await run()).toEqual({ 'session-limits-since': 0, 'wopi-revocations': 0 });
+  });
+});
diff --git a/lib/auth/session-age.ts b/lib/auth/session-age.ts
index 50ef61536..d21ddcec1 100644
--- a/lib/auth/session-age.ts
+++ b/lib/auth/session-age.ts
@@ -32,7 +32,7 @@ import { decryptPayload, encryptPayload } from '@/lib/auth/crypto';
 import { hasSessionSecret } from '@/lib/auth/session-secret';
 import { getCookieOptions } from '@/lib/oauth/cookie-config';
 import { logger } from '@/lib/logger';
-import { getStore, isSharedMode } from '@/lib/shared-store';
+import { getStore, isSharedMode, type CollectionOptions } from '@/lib/shared-store';
 
 export { SESSION_TOO_OLD } from '@/lib/session-policy/constants';
 
@@ -90,8 +90,12 @@ function memo(): { since: Promise<number> | null } {
  * The time in the shared store (#1066). Its local layout is today's file in
  * the state dir, which local mode keeps writing itself (with O_EXCL).
  */
-export function sessionLimitsCollection() {
-  return getStore().collection('session-limits', { local: { dir: () => getStateDir() } });
+export const SESSION_LIMITS_COLLECTION = 'session-limits';
+export const SESSION_LIMITS_ID = ENFORCED_SINCE_FILE;
+export const sessionLimitsLayout: CollectionOptions = { local: { dir: () => getStateDir() } };
+
+function sessionLimitsCollection() {
+  return getStore().collection(SESSION_LIMITS_COLLECTION, sessionLimitsLayout);
 }
 
 function parseTime(text: string): number | null {
diff --git a/lib/shared-store/import/auth.ts b/lib/shared-store/import/auth.ts
new file mode 100644
index 000000000..725c8bb20
--- /dev/null
+++ b/lib/shared-store/import/auth.ts
@@ -0,0 +1,45 @@
+import { SESSION_LIMITS_COLLECTION, SESSION_LIMITS_ID, sessionLimitsLayout } from '@/lib/auth/session-age';
+import { REVOCATIONS_ID, WOPI_COLLECTION, wopiRevocationsLayout } from '@/lib/wopi/revocation';
+import { getStore } from '../index';
+import type { ImportStep } from '../import';
+import { localCollection } from '../local';
+import type { CollectionOptions } from '../types';
+
+/**
+ * Import steps of part `auth` (#1066): the auth state that outlives a
+ * restart.
+ *
+ * - session-limits-since: when the server first enforced the maximum
+ *   session length. Without it the shared store would record a new time and
+ *   legacy sessions would get a fresh allowance.
+ * - WOPI revocations: office editor tokens revoked at sign-out, for up to
+ *   six hours.
+ *
+ * Not imported, because they don't outlive the switch in any way that
+ * matters:
+ * - pairing grants, codes and the hand-off codes: in memory only, gone with
+ *   the restart that turns on the shared store, as on any restart (they last
+ *   two to five minutes);
+ * - impersonation markers: they refuse a used hand-off link for at most 420
+ *   seconds, and the links themselves live five minutes at most. Moving an
+ *   install takes the deployment down for longer than that.
+ * - sign-in budgets: counters of 15 minutes to a day; they start empty, as
+ *   they do after every restart today.
+ */
+
+function copyStep(name: string, collection: string, layout: CollectionOptions, id: string): ImportStep {
+  return {
+    name,
+    async run() {
+      const doc = await localCollection(collection, layout).get(id);
+      if (!doc) return 0;
+      const written = await getStore().collection(collection, layout).put(id, doc.data, { ifVersion: null });
+      return written.ok ? 1 : 0;
+    },
+  };
+}
+
+export const steps: ImportStep[] = [
+  copyStep('session-limits-since', SESSION_LIMITS_COLLECTION, sessionLimitsLayout, SESSION_LIMITS_ID),
+  copyStep('wopi-revocations', WOPI_COLLECTION, wopiRevocationsLayout, REVOCATIONS_ID),
+];
diff --git a/lib/wopi/revocation.ts b/lib/wopi/revocation.ts
index f8a0c9c1a..ecd8a6054 100644
--- a/lib/wopi/revocation.ts
+++ b/lib/wopi/revocation.ts
@@ -4,7 +4,7 @@ import type { cookies } from 'next/headers';
 import { getStateDir, getStatePath } from '@/lib/admin/paths';
 import { logger } from '@/lib/logger';
 import { getCookieOptions } from '@/lib/oauth/cookie-config';
-import { getStore, isSharedMode } from '@/lib/shared-store';
+import { getStore, isSharedMode, type CollectionOptions } from '@/lib/shared-store';
 import { WOPI_TOKEN_TTL_MS, type WopiTokenPayload } from '@/lib/wopi/token';
 
 /**
@@ -29,18 +29,21 @@ type CookieStore = Awaited<ReturnType<typeof cookies>>;
 
 export const WOPI_BROWSER_COOKIE = 'bulwark_wopi';
 const REVOCATIONS_FILE = 'wopi-revocations.json';
-const REVOCATIONS_ID = 'revocations.json';
+export const WOPI_COLLECTION = 'wopi';
+export const REVOCATIONS_ID = 'revocations.json';
 
 /** The revocations document; locally today's file in the state dir. */
-export function wopiRevocationsCollection() {
-  return getStore().collection('wopi', {
-    local: {
-      dir: () => getStateDir(),
-      file: () => REVOCATIONS_FILE,
-      idOf: (file) => (file === REVOCATIONS_FILE ? REVOCATIONS_ID : null),
-      tmpName: (target) => `${target}.${process.pid}.tmp`,
-    },
-  });
+export const wopiRevocationsLayout: CollectionOptions = {
+  local: {
+    dir: () => getStateDir(),
+    file: () => REVOCATIONS_FILE,
+    idOf: (file) => (file === REVOCATIONS_FILE ? REVOCATIONS_ID : null),
+    tmpName: (target) => `${target}.${process.pid}.tmp`,
+  },
+};
+
+function wopiRevocationsCollection() {
+  return getStore().collection(WOPI_COLLECTION, wopiRevocationsLayout);
 }
 
 function browserBinding(browserId: string): string {