diff --git a/scripts/e2e/openwebui-probe.mjs b/scripts/e2e/openwebui-probe.mjs
index f173b8f73df8..99ef9161e1b7 100644
--- a/scripts/e2e/openwebui-probe.mjs
+++ b/scripts/e2e/openwebui-probe.mjs
@@ -7,14 +7,15 @@ const email = process.env.OPENWEBUI_ADMIN_EMAIL ?? "";
 const password = process.env.OPENWEBUI_ADMIN_PASSWORD ?? "";
 const expectedNonce = process.env.OPENWEBUI_EXPECTED_NONCE ?? "";
 const prompt = process.env.OPENWEBUI_PROMPT ?? "";
+const MAX_TIMER_TIMEOUT_MS = 2_147_000_000;
 const modelAttempts = readPositiveInt("OPENWEBUI_MODEL_ATTEMPTS", 72);
-const modelRetryMs = readNonNegativeInt("OPENWEBUI_MODEL_RETRY_MS", 5000);
-const fetchTimeoutMs = readPositiveInt("OPENWEBUI_FETCH_TIMEOUT_MS", 720000);
-const controlTimeoutMs = readPositiveInt(
+const modelRetryMs = readNonNegativeTimerMs("OPENWEBUI_MODEL_RETRY_MS", 5000);
+const fetchTimeoutMs = readPositiveTimerMs("OPENWEBUI_FETCH_TIMEOUT_MS", 720000);
+const controlTimeoutMs = readPositiveTimerMs(
   "OPENWEBUI_CONTROL_TIMEOUT_MS",
   Math.min(fetchTimeoutMs, 30000),
 );
-const chatTimeoutMs = readPositiveInt("OPENWEBUI_CHAT_TIMEOUT_MS", fetchTimeoutMs);
+const chatTimeoutMs = readPositiveTimerMs("OPENWEBUI_CHAT_TIMEOUT_MS", fetchTimeoutMs);
 const responseBodyMaxBytes = readPositiveInt("OPENWEBUI_RESPONSE_BODY_MAX_BYTES", 1024 * 1024);
 const smokeMode =
   process.env.OPENWEBUI_SMOKE_MODE ?? process.env.OPENCLAW_OPENWEBUI_SMOKE_MODE ?? "chat";
@@ -65,6 +66,20 @@ function readNonNegativeInt(name, fallback) {
   return parsed;
 }
 
+function clampTimerTimeoutMs(valueMs, minMs = 1) {
+  const min = Math.max(0, Math.floor(minMs));
+  const value = Number.isFinite(valueMs) ? valueMs : min;
+  return Math.min(Math.max(Math.floor(value), min), MAX_TIMER_TIMEOUT_MS);
+}
+
+function readPositiveTimerMs(name, fallback) {
+  return clampTimerTimeoutMs(readPositiveInt(name, fallback));
+}
+
+function readNonNegativeTimerMs(name, fallback) {
+  return clampTimerTimeoutMs(readNonNegativeInt(name, fallback), 0);
+}
+
 function createTimeoutError(label, timeoutMs) {
   const error = new Error(`${label} timed out after ${timeoutMs}ms`);
   error.code = "ETIMEDOUT";
@@ -72,14 +87,15 @@ function createTimeoutError(label, timeoutMs) {
 }
 
 async function withRequestTimeout(label, timeoutMs, run) {
+  const resolvedTimeoutMs = clampTimerTimeoutMs(timeoutMs);
   const controller = new AbortController();
-  const timeoutError = createTimeoutError(label, timeoutMs);
+  const timeoutError = createTimeoutError(label, resolvedTimeoutMs);
   let timer;
   const timeoutPromise = new Promise((_, reject) => {
     timer = setTimeout(() => {
       controller.abort(timeoutError);
       reject(timeoutError);
-    }, timeoutMs);
+    }, resolvedTimeoutMs);
     timer.unref?.();
   });
   try {
@@ -138,7 +154,7 @@ function buildAuthHeaders(token, cookie) {
 
 function sleep(ms) {
   return new Promise((resolve) => {
-    setTimeout(resolve, ms);
+    setTimeout(resolve, clampTimerTimeoutMs(ms, 0));
   });
 }
 
diff --git a/test/e2e/qa-lab/runtime/openwebui-probe.e2e.test.ts b/test/e2e/qa-lab/runtime/openwebui-probe.e2e.test.ts
index 188bfea6934c..ab36ddaf5714 100644
--- a/test/e2e/qa-lab/runtime/openwebui-probe.e2e.test.ts
+++ b/test/e2e/qa-lab/runtime/openwebui-probe.e2e.test.ts
@@ -4,6 +4,7 @@ import { readFileSync } from "node:fs";
 import { createServer, type IncomingMessage, type Server as HttpServer } from "node:http";
 import { createServer as createTcpServer, type Server as TcpServer, type Socket } from "node:net";
 import path from "node:path";
+import { MAX_TIMER_TIMEOUT_MS } from "@openclaw/normalization-core/number-coercion";
 import { describe, expect, it } from "vitest";
 import { createBoundedChildOutput } from "../../../helpers/bounded-child-output.js";
 
@@ -361,11 +362,13 @@ describe("scripts/e2e/openwebui-probe.mjs", () => {
   it("passes in models mode when Open WebUI exposes the OpenClaw model", async () => {
     const server = createServer((request, response) => {
       if (request.url === "/api/v1/auths/signin") {
-        response.writeHead(200, {
-          "content-type": "application/json",
-          "set-cookie": "openwebui-session=test; Path=/",
-        });
-        response.end(JSON.stringify({ token: "test-token" }));
+        setTimeout(() => {
+          response.writeHead(200, {
+            "content-type": "application/json",
+            "set-cookie": "openwebui-session=test; Path=/",
+          });
+          response.end(JSON.stringify({ token: "test-token" }));
+        }, 25);
         return;
       }
       if (request.url === "/api/models") {
@@ -379,7 +382,10 @@ describe("scripts/e2e/openwebui-probe.mjs", () => {
     });
     const baseUrl = await listen(server);
     try {
-      const result = await runProbe(baseUrl);
+      const result = await runProbe(baseUrl, {
+        OPENWEBUI_CONTROL_TIMEOUT_MS: String(MAX_TIMER_TIMEOUT_MS + 1),
+        OPENWEBUI_FETCH_TIMEOUT_MS: String(MAX_TIMER_TIMEOUT_MS + 1),
+      });
 
       expect(result.status).toBe(0);
       expect(JSON.parse(result.stdout)).toMatchObject({