diff --git a/src/infra/stale-lock-file.test.ts b/src/infra/stale-lock-file.test.ts
index b792895fe7cb..8b7e3d7ac31e 100644
--- a/src/infra/stale-lock-file.test.ts
+++ b/src/infra/stale-lock-file.test.ts
@@ -2,19 +2,52 @@ import { describe, expect, it } from "vitest";
 import { shouldRemoveDeadOwnerOrExpiredLock } from "./stale-lock-file.js";
 
 describe("stale lock file ownership", () => {
-  it("treats permission-denied process probes as not definitely dead", () => {
+  it("keeps expired locks when a pid owner is not definitely dead", () => {
     expect(
       shouldRemoveDeadOwnerOrExpiredLock({
         payload: {
           pid: 123,
-          createdAt: new Date(Date.now() - 60_000).toISOString(),
+          createdAt: "2026-05-23T00:00:00.000Z",
         },
         staleMs: 10,
+        nowMs: Date.parse("2026-05-23T00:00:11.000Z"),
         isPidDefinitelyDead: () => false,
       }),
     ).toBe(false);
   });
 
+  it("removes locks when the owner pid starttime changed", () => {
+    expect(
+      shouldRemoveDeadOwnerOrExpiredLock({
+        payload: {
+          pid: 123,
+          createdAt: "2026-05-23T00:00:00.000Z",
+          starttime: 111,
+        },
+        staleMs: 60_000,
+        nowMs: Date.parse("2026-05-23T00:00:10.000Z"),
+        isPidDefinitelyDead: () => false,
+        getProcessStartTime: () => 222,
+      }),
+    ).toBe(true);
+  });
+
+  it("does not remove locks when the owner pid starttime still matches", () => {
+    expect(
+      shouldRemoveDeadOwnerOrExpiredLock({
+        payload: {
+          pid: 123,
+          createdAt: "2026-05-23T00:00:00.000Z",
+          starttime: 111,
+        },
+        staleMs: 10,
+        nowMs: Date.parse("2026-05-23T00:00:11.000Z"),
+        isPidDefinitelyDead: () => false,
+        getProcessStartTime: () => 111,
+      }),
+    ).toBe(false);
+  });
+
   it("only removes pid-owned locks when the owner is definitely dead", () => {
     expect(
       shouldRemoveDeadOwnerOrExpiredLock({
@@ -27,4 +60,16 @@ describe("stale lock file ownership", () => {
       }),
     ).toBe(true);
   });
+
+  it("removes expired pidless locks", () => {
+    expect(
+      shouldRemoveDeadOwnerOrExpiredLock({
+        payload: {
+          createdAt: "2026-05-23T00:00:00.000Z",
+        },
+        staleMs: 10,
+        nowMs: Date.parse("2026-05-23T00:00:11.000Z"),
+      }),
+    ).toBe(true);
+  });
 });
diff --git a/src/infra/stale-lock-file.ts b/src/infra/stale-lock-file.ts
index 79ea94cc3e19..222a6d9a310a 100644
--- a/src/infra/stale-lock-file.ts
+++ b/src/infra/stale-lock-file.ts
@@ -1,8 +1,12 @@
-import { isPidDefinitelyDead as defaultIsPidDefinitelyDead } from "../shared/pid-alive.js";
+import {
+  getProcessStartTime as defaultGetProcessStartTime,
+  isPidDefinitelyDead as defaultIsPidDefinitelyDead,
+} from "../shared/pid-alive.js";
 
 export type LockFileOwnerPayload = {
   pid?: number;
   createdAt?: string;
+  starttime?: number;
 };
 
 export function readLockFileOwnerPayload(
@@ -14,6 +18,7 @@ export function readLockFileOwnerPayload(
   return {
     pid: typeof payload.pid === "number" ? payload.pid : undefined,
     createdAt: typeof payload.createdAt === "string" ? payload.createdAt : undefined,
+    starttime: typeof payload.starttime === "number" ? payload.starttime : undefined,
   };
 }
 
@@ -22,14 +27,27 @@ export function shouldRemoveDeadOwnerOrExpiredLock(params: {
   staleMs: number;
   nowMs?: number;
   isPidDefinitelyDead?: (pid: number) => boolean;
+  getProcessStartTime?: (pid: number) => number | null;
 }): boolean {
   const payload = readLockFileOwnerPayload(params.payload);
   if (payload?.pid) {
+    // Timestamp age alone cannot prove the owner stopped writing. Only a
+    // mismatched process start time proves PID reuse while the PID is alive.
+    if (payload.starttime !== undefined) {
+      const currentStarttime = (params.getProcessStartTime ?? defaultGetProcessStartTime)(
+        payload.pid,
+      );
+      if (currentStarttime !== null && currentStarttime !== payload.starttime) {
+        return true;
+      }
+    }
     return (params.isPidDefinitelyDead ?? defaultIsPidDefinitelyDead)(payload.pid);
   }
   if (payload?.createdAt) {
     const createdAt = Date.parse(payload.createdAt);
-    return !Number.isFinite(createdAt) || (params.nowMs ?? Date.now()) - createdAt > params.staleMs;
+    if (!Number.isFinite(createdAt) || (params.nowMs ?? Date.now()) - createdAt > params.staleMs) {
+      return true;
+    }
   }
   return false;
 }
diff --git a/src/plugin-sdk/file-lock.test.ts b/src/plugin-sdk/file-lock.test.ts
index 921cbbd9a11f..ffc8728ac715 100644
--- a/src/plugin-sdk/file-lock.test.ts
+++ b/src/plugin-sdk/file-lock.test.ts
@@ -117,7 +117,7 @@ describe("acquireFileLock", () => {
     await expect(fs.readFile(lockPath, "utf8")).resolves.toBe("{");
   });
 
-  it("keeps a reported stale lock when its owner pid is alive", async () => {
+  it("keeps an expired lock when its live owner has no starttime proof", async () => {
     const filePath = path.join(tempDir, "live-owner");
     const lockPath = `${filePath}.lock`;
     const options = {
diff --git a/src/plugin-sdk/file-lock.ts b/src/plugin-sdk/file-lock.ts
index 06b5208dd623..0ab2f2d9f87a 100644
--- a/src/plugin-sdk/file-lock.ts
+++ b/src/plugin-sdk/file-lock.ts
@@ -5,6 +5,7 @@ import {
   resetFileLockManagerForTest,
 } from "@openclaw/fs-safe/file-lock";
 import { shouldRemoveDeadOwnerOrExpiredLock } from "../infra/stale-lock-file.js";
+import { getProcessStartTime } from "../shared/pid-alive.js";
 
 export type FileLockOptions = {
   retries: {
@@ -86,7 +87,17 @@ export async function acquireFileLock(
       retry: options.retries,
       staleRecovery: "remove-if-unchanged",
       allowReentrant: true,
-      payload: () => ({ pid: process.pid, createdAt: new Date().toISOString() }),
+      payload: () => {
+        const payload: Record<string, unknown> = {
+          pid: process.pid,
+          createdAt: new Date().toISOString(),
+        };
+        const starttime = getProcessStartTime(process.pid);
+        if (starttime !== null) {
+          payload.starttime = starttime;
+        }
+        return payload;
+      },
       shouldReclaim: shouldReclaimPluginLock,
       shouldRemoveStaleLock: (snapshot) =>
         shouldRemoveDeadOwnerOrExpiredLock({