diff --git a/scripts/prepare-extension-package-boundary-artifacts.mjs b/scripts/prepare-extension-package-boundary-artifacts.mjs
index 2bf43fb72a9f..e0acdbac30f8 100644
--- a/scripts/prepare-extension-package-boundary-artifacts.mjs
+++ b/scripts/prepare-extension-package-boundary-artifacts.mjs
@@ -18,6 +18,7 @@ const ROOT_SHIMS_MAX_OLD_SPACE_SIZE =
 const ROOT_SHIMS_NODE_OPTIONS =
   `${process.env.NODE_OPTIONS ?? ""} --max-old-space-size=${ROOT_SHIMS_MAX_OLD_SPACE_SIZE}`.trim();
 const NODE_STEP_ABORT_KILL_GRACE_MS = 1_000;
+const MAX_TIMER_TIMEOUT_MS = 2_147_000_000;
 const NODE_STEP_PARENT_SIGNALS = ["SIGHUP", "SIGINT", "SIGTERM"];
 const NODE_STEP_PARENT_SIGNAL_EXIT_CODES = new Map([
   ["SIGHUP", 129],
@@ -469,10 +470,19 @@ function installNodeStepParentSignalForwarders() {
   });
 }
 
+function resolveNodeStepTimerTimeoutMs(valueMs) {
+  const value = Number(valueMs);
+  if (!Number.isFinite(value)) {
+    return MAX_TIMER_TIMEOUT_MS;
+  }
+  return Math.min(Math.max(Math.floor(value), 1), MAX_TIMER_TIMEOUT_MS);
+}
+
 /**
  * Runs one artifact step with timeout, abort propagation, and prefixed output.
  */
 export function runNodeStep(label, args, timeoutMs, params = {}) {
+  const resolvedTimeoutMs = resolveNodeStepTimerTimeoutMs(timeoutMs);
   const abortController = params.abortController;
   const spawnImpl = params.spawnImpl ?? spawn;
   installNodeStepParentSignalForwarders();
@@ -555,8 +565,8 @@ export function runNodeStep(label, args, timeoutMs, params = {}) {
       stdoutWriter.flush();
       stderrWriter.flush();
       abortSiblingSteps(abortController);
-      rejectPromise(new Error(`${label} timed out after ${timeoutMs}ms`));
-    }, timeoutMs);
+      rejectPromise(new Error(`${label} timed out after ${resolvedTimeoutMs}ms`));
+    }, resolvedTimeoutMs);
     abortController?.signal.addEventListener("abort", abortStep, { once: true });
 
     child.stdout.setEncoding("utf8");
diff --git a/test/scripts/prepare-extension-package-boundary-artifacts.test.ts b/test/scripts/prepare-extension-package-boundary-artifacts.test.ts
index 9e18a5b8352b..145a2d7dde6f 100644
--- a/test/scripts/prepare-extension-package-boundary-artifacts.test.ts
+++ b/test/scripts/prepare-extension-package-boundary-artifacts.test.ts
@@ -7,6 +7,7 @@ import os from "node:os";
 import path from "node:path";
 import { setTimeout as delay } from "node:timers/promises";
 import { pathToFileURL } from "node:url";
+import { MAX_TIMER_TIMEOUT_MS } from "@openclaw/normalization-core/number-coercion";
 import { afterEach, describe, expect, it, vi } from "vitest";
 import { resolveWindowsTaskkillPath } from "../../scripts/lib/windows-taskkill.mjs";
 import {
@@ -317,6 +318,16 @@ describe("prepare-extension-package-boundary-artifacts", () => {
     expect(signals).toEqual(["SIGKILL"]);
   });
 
+  it("clamps oversized prep step timers before scheduling", async () => {
+    await expect(
+      runNodeStep(
+        "slow-success",
+        ["--eval", "setTimeout(() => process.exit(0), 25);"],
+        MAX_TIMER_TIMEOUT_MS + 1,
+      ),
+    ).resolves.toBeUndefined();
+  });
+
   it.runIf(process.platform !== "win32")("kills timed-out prep step process groups", async () => {
     const rootDir = fs.mkdtempSync(path.join(os.tmpdir(), "openclaw-boundary-timeout-group-"));
     tempRoots.add(rootDir);