diff --git a/extensions/whatsapp/src/creds-persistence.test.ts b/extensions/whatsapp/src/creds-persistence.test.ts
new file mode 100644
index 00000000000..6db058e2456
--- /dev/null
+++ b/extensions/whatsapp/src/creds-persistence.test.ts
@@ -0,0 +1,25 @@
+import { MAX_TIMER_TIMEOUT_MS } from "openclaw/plugin-sdk/number-runtime";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { enqueueCredsSave, waitForCredsSaveQueueWithTimeout } from "./creds-persistence.js";
+
+describe("creds-persistence", () => {
+  afterEach(() => {
+    vi.useRealTimers();
+    vi.restoreAllMocks();
+  });
+
+  it("caps oversized credential flush timeouts before scheduling", async () => {
+    vi.useFakeTimers();
+    const timeoutSpy = vi.spyOn(globalThis, "setTimeout");
+    const authDir = "oversized-timeout";
+    enqueueCredsSave(
+      authDir,
+      () => undefined,
+      () => undefined,
+    );
+
+    await waitForCredsSaveQueueWithTimeout(authDir, Number.MAX_SAFE_INTEGER);
+
+    expect(timeoutSpy).toHaveBeenCalledWith(expect.any(Function), MAX_TIMER_TIMEOUT_MS);
+  });
+});
diff --git a/extensions/whatsapp/src/creds-persistence.ts b/extensions/whatsapp/src/creds-persistence.ts
index 204af357677..9ad82529022 100644
--- a/extensions/whatsapp/src/creds-persistence.ts
+++ b/extensions/whatsapp/src/creds-persistence.ts
@@ -1,3 +1,4 @@
+import { resolveTimerTimeoutMs } from "openclaw/plugin-sdk/number-runtime";
 import { replaceFileAtomic } from "openclaw/plugin-sdk/security-runtime";
 import { assertWebCredsPathRegularFileOrMissing, resolveWebCredsPath } from "./creds-files.js";
 
@@ -71,11 +72,12 @@ export async function waitForCredsSaveQueueWithTimeout(
   authDir: string,
   timeoutMs = CREDS_SAVE_FLUSH_TIMEOUT_MS,
 ): Promise<CredsQueueWaitResult> {
+  const boundedTimeoutMs = resolveTimerTimeoutMs(timeoutMs, CREDS_SAVE_FLUSH_TIMEOUT_MS, 0);
   let flushTimeout: ReturnType<typeof setTimeout> | undefined;
   return await Promise.race([
     waitForCredsSaveQueue(authDir).then(() => "drained" as const),
     new Promise<CredsQueueWaitResult>((resolve) => {
-      flushTimeout = setTimeout(() => resolve("timed_out"), timeoutMs);
+      flushTimeout = setTimeout(() => resolve("timed_out"), boundedTimeoutMs);
     }),
   ]).finally(() => {
     if (flushTimeout) {