@@ -967,3 +967,39 @@ test('an app claim of a dead owner is released by release --stale like any claim
   );
   assert.equal(fs.existsSync(file), false);
 });
+
+test("an app claim taken over this daemon's abandoned whole-Mac claim leaves other daemons' apps free", async () => {
+  const root = useClaimsRoot();
+  const whole = await acquireDeviceClaim({
+    device: mac,
+    session: 'desktop',
+    workspace: '/desktop',
+    stateDir: root,
+  });
+  assert.equal(whole.status, 'acquired');
+  if (whole.status !== 'acquired') return;
+  assert.equal(await abandonDeviceClaim(whole.ownership), 'abandoned');
+
+  const app = await acquireDeviceClaim({
+    device: mac,
+    session: 'app',
+    workspace: '/app',
+    stateDir: root,
+    app: { bundleId: 'com.example.one' },
+  });
+  assert.equal(app.status, 'acquired');
+  if (app.status !== 'acquired') return;
+  assert.deepEqual(app.ownership.app, { bundleId: 'com.example.one' });
+  assert.equal(fs.existsSync(resolveDeviceClaimPath(canonicalLocalDeviceKey(mac))), false);
+
+  const foreignStateDir = path.join(root, 'foreign');
+  fs.mkdirSync(foreignStateDir);
+  const foreign = await acquireDeviceClaim({
+    device: mac,
+    session: 'foreign',
+    workspace: '/foreign',
+    stateDir: foreignStateDir,
+    app: { bundleId: 'com.example.two' },
+  });
+  assert.equal(foreign.status, 'acquired');
+});
@@ -107,13 +107,31 @@ export async function acquireDeviceClaim(params: {
       if (held) return { status: 'conflict', conflict: held };
     }
     const appKey = appScopedDeviceKey(deviceKey, app.bundleId);
-    return await withDeviceClaimLock(
+    const acquired = await withDeviceClaimLock(
       appKey,
       async () => await claimHeldDevice({ ...params, deviceKey: appKey, identity, app }),
     );
+    if (acquired.status !== 'acquired') return acquired;
+    removeSupersededDeviceClaim(deviceKey);
+    const tookOver =
+      acquired.tookOver ?? (deviceClaim.status === 'available' ? deviceClaim.tookOver : undefined);
+    return tookOver ? { ...acquired, tookOver } : acquired;
   });
 }
 
+/**
+ * An app acquisition that found the device key available leaves no record there: what remains can
+ * only be this daemon's own abandoned whole-device claim, which would otherwise keep fencing every
+ * other daemon's apps. The caller holds the device key's lock.
+ */
+function removeSupersededDeviceClaim(deviceKey: string): void {
+  try {
+    fs.unlinkSync(resolveDeviceClaimPath(deviceKey));
+  } catch (error) {
+    if ((error as NodeJS.ErrnoException).code !== 'ENOENT') throw error;
+  }
+}
+
 /**
  * #1320 `transient-exclusive`: exclusive ownership for the duration of one
  * sessionless device mutation. Identical to a session claim except that a claim