diff --git a/server/licensing/refresh.test.ts b/server/licensing/refresh.test.ts
index a8c3b2bb..48c43641 100644
--- a/server/licensing/refresh.test.ts
+++ b/server/licensing/refresh.test.ts
@@ -159,4 +159,37 @@ describe('performRefresh', () => {
     expect(state.refreshToken).toBe('old-rt')
     expect(state.lastRefreshError).toBe('Connection timeout')
   })
+
+  it('keeps the previous binding when cloud returns an invalid certificate', async () => {
+    const db = makeDb()
+    await seedBinding(db, {
+      [LICENSE_KEYS.cachedCert]: 'old-cert',
+      [LICENSE_KEYS.cachedExpiresAt]: '1234567890',
+    })
+
+    const cert = sign(TEST_SECRET, {
+      account_id: 'acct-1',
+      instance_id: 'wrong-instance',
+      plan: 'pro',
+      features: ['white_label'],
+      issued_at: new Date().toISOString(),
+      expires_at: futureIso(3_600_000),
+    })
+
+    vi.mocked(fetch).mockResolvedValueOnce({
+      ok: true,
+      status: 200,
+      json: async () => ({ refresh_token: 'new-rt', certificate: cert }),
+      text: async () => '',
+    } as unknown as Response)
+
+    await performRefresh(db, 'https://cloud.zpan.space')
+
+    const { loadLicenseState } = await import('./license-state')
+    const state = await loadLicenseState(db)
+    expect(state.refreshToken).toBe('old-rt')
+    expect(state.cachedCert).toBe('old-cert')
+    expect(state.cachedExpiresAt).toBe(1234567890)
+    expect(state.lastRefreshError).toBe('Invalid certificate from cloud')
+  })
 })
diff --git a/server/licensing/refresh.ts b/server/licensing/refresh.ts
index 774ad3f7..0b20e4e5 100644
--- a/server/licensing/refresh.ts
+++ b/server/licensing/refresh.ts
@@ -5,6 +5,8 @@ import { invalidateEntitlementCache } from './entitlement'
 import { clearLicenseBinding, LICENSE_KEYS, loadLicenseState, setLicenseOptions } from './license-state'
 import { verifyCertificate } from './verify'
 
+const INVALID_CERTIFICATE_ERROR = 'Invalid certificate from cloud'
+
 function normaliseCert(raw: string, instanceId: string): { cert: string; entitlement: LicenseEntitlement | null } {
   const entitlement = verifyCertificate(raw, instanceId)
   return { cert: raw, entitlement }
@@ -17,13 +19,17 @@ export async function performRefresh(db: Database, baseUrl: string): Promise<voi
   try {
     const data = await refreshEntitlement(baseUrl, state.refreshToken)
     const { cert, entitlement } = normaliseCert(data.certificate, state.instanceId)
+    if (!entitlement) {
+      await setLicenseOptions(db, {
+        [LICENSE_KEYS.lastRefreshError]: INVALID_CERTIFICATE_ERROR,
+      })
+      return
+    }
 
     await setLicenseOptions(db, {
       [LICENSE_KEYS.refreshToken]: data.refresh_token,
       [LICENSE_KEYS.cachedCert]: cert,
-      [LICENSE_KEYS.cachedExpiresAt]: entitlement
-        ? String(Math.floor(new Date(entitlement.expires_at).getTime() / 1000))
-        : null,
+      [LICENSE_KEYS.cachedExpiresAt]: String(Math.floor(new Date(entitlement.expires_at).getTime() / 1000)),
       [LICENSE_KEYS.lastRefreshAt]: String(Math.floor(Date.now() / 1000)),
       [LICENSE_KEYS.lastRefreshError]: null,
     })