diff --git a/extension/src/popup/components/__tests__/devices.test.ts b/extension/src/popup/components/__tests__/devices.test.ts
index 7e73520..60c31b7 100644
--- a/extension/src/popup/components/__tests__/devices.test.ts
+++ b/extension/src/popup/components/__tests__/devices.test.ts
@@ -33,11 +33,16 @@ describe('devices view', () => {
     vi.clearAllMocks();
   });
 
+  // The component fires list_devices + list_revoked in parallel via Promise.all,
+  // so every render needs both mocked. Helper makes the per-test setup readable.
+  function mockListPair(devices: unknown[], revoked: unknown[] = []): void {
+    (sendMessage as ReturnType<typeof vi.fn>)
+      .mockResolvedValueOnce({ ok: true, data: { devices } })
+      .mockResolvedValueOnce({ ok: true, data: { revoked } });
+  }
+
   it('renders empty state when no devices', async () => {
-    (sendMessage as ReturnType<typeof vi.fn>).mockResolvedValueOnce({
-      ok: true,
-      data: { devices: [] },
-    });
+    mockListPair([]);
 
     await renderDevices(app);
 
@@ -45,15 +50,10 @@ describe('devices view', () => {
   });
 
   it('renders devices with "you" indicator on current device', async () => {
-    (sendMessage as ReturnType<typeof vi.fn>).mockResolvedValueOnce({
-      ok: true,
-      data: {
-        devices: [
-          { name: 'Chrome on Linux', public_key: 'abc', added_at: 1000 },
-          { name: 'CLI', public_key: 'def', added_at: 500 },
-        ],
-      },
-    });
+    mockListPair([
+      { name: 'Chrome on Linux', public_key: 'abc', added_at: 1000 },
+      { name: 'CLI', public_key: 'def', added_at: 500 },
+    ]);
 
     await renderDevices(app);
 
@@ -68,23 +68,15 @@ describe('devices view', () => {
 
   it('shows unregistered banner when current device not in list', async () => {
     (chrome.storage.local.get as ReturnType<typeof vi.fn>).mockResolvedValueOnce({ device_name: 'Unknown' });
-    (sendMessage as ReturnType<typeof vi.fn>).mockResolvedValueOnce({
-      ok: true,
-      data: {
-        devices: [{ name: 'CLI', public_key: 'abc', added_at: 1000 }],
-      },
-    });
+    mockListPair([{ name: 'CLI', public_key: 'abc', added_at: 1000 }]);
 
     await renderDevices(app);
 
-    expect(app.innerHTML).toContain('This device is not registered');
+    expect(app.innerHTML).toContain("This device isn't registered");
   });
 
   it('back button navigates to list', async () => {
-    (sendMessage as ReturnType<typeof vi.fn>).mockResolvedValueOnce({
-      ok: true,
-      data: { devices: [] },
-    });
+    mockListPair([]);
 
     await renderDevices(app);
     app.querySelector<HTMLButtonElement>('#back-btn')?.click();
@@ -94,10 +86,7 @@ describe('devices view', () => {
 
   it('clicking register button reveals an inline name input', async () => {
     (chrome.storage.local.get as ReturnType<typeof vi.fn>).mockResolvedValueOnce({ device_name: 'Unknown' });
-    (sendMessage as ReturnType<typeof vi.fn>).mockResolvedValueOnce({
-      ok: true,
-      data: { devices: [{ name: 'CLI', public_key: 'k', added_at: 1 }] },
-    });
+    mockListPair([{ name: 'CLI', public_key: 'k', added_at: 1 }]);
 
     await renderDevices(app);
     app.querySelector<HTMLButtonElement>('#register-btn')!.click();
@@ -108,13 +97,15 @@ describe('devices view', () => {
 
   it('confirming register sends register_this_device with the entered name', async () => {
     (chrome.storage.local.get as ReturnType<typeof vi.fn>).mockResolvedValueOnce({ device_name: 'Unknown' });
-    // Initial list_devices.
-    (sendMessage as ReturnType<typeof vi.fn>)
-      .mockResolvedValueOnce({ ok: true, data: { devices: [{ name: 'CLI', public_key: 'k', added_at: 1 }] } })
-      // register_this_device.
-      .mockResolvedValueOnce({ ok: true })
-      // Re-render's list_devices.
-      .mockResolvedValueOnce({ ok: true, data: { devices: [{ name: 'CLI', public_key: 'k', added_at: 1 }, { name: 'Test Browser', public_key: 'q', added_at: 2 }] } });
+    // Initial render: list_devices + list_revoked.
+    mockListPair([{ name: 'CLI', public_key: 'k', added_at: 1 }]);
+    // register_this_device.
+    (sendMessage as ReturnType<typeof vi.fn>).mockResolvedValueOnce({ ok: true });
+    // Re-render: list_devices + list_revoked.
+    mockListPair([
+      { name: 'CLI', public_key: 'k', added_at: 1 },
+      { name: 'Test Browser', public_key: 'q', added_at: 2 },
+    ]);
     // Re-render also re-reads device_name from storage.
     (chrome.storage.local.get as ReturnType<typeof vi.fn>).mockResolvedValueOnce({ device_name: 'Test Browser' });
 
diff --git a/extension/src/service-worker/__tests__/devices.test.ts b/extension/src/service-worker/__tests__/devices.test.ts
index 5384f95..bee353d 100644
--- a/extension/src/service-worker/__tests__/devices.test.ts
+++ b/extension/src/service-worker/__tests__/devices.test.ts
@@ -3,10 +3,19 @@ import { readDevices, addDevice, revokeDevice } from '../devices';
 import type { GitHost } from '../git-host';
 
 function makeGitHost(devicesJson = '{"devices":[]}'): GitHost {
-  let stored = devicesJson;
+  // Per-path storage — revokeDevice writes devices.json AND revoked.json,
+  // so a single slot would corrupt the second read.
+  const files = new Map<string, string>();
+  files.set('.relicario/devices.json', devicesJson);
   return {
-    readFile: vi.fn().mockImplementation(async () => new TextEncoder().encode(stored)),
-    writeFile: vi.fn().mockImplementation(async (_p, bytes) => { stored = new TextDecoder().decode(bytes); }),
+    readFile: vi.fn().mockImplementation(async (path: string) => {
+      const content = files.get(path);
+      if (content === undefined) throw new Error(`404: ${path}`);
+      return new TextEncoder().encode(content);
+    }),
+    writeFile: vi.fn().mockImplementation(async (path: string, bytes: Uint8Array) => {
+      files.set(path, new TextDecoder().decode(bytes));
+    }),
     deleteFile: vi.fn(),
     listDir: vi.fn(),
     putBlob: vi.fn(),