diff --git a/apps/extension/clip-time.test.mjs b/apps/extension/clip-time.test.mjs
index 61568e77..f7ef905b 100644
--- a/apps/extension/clip-time.test.mjs
+++ b/apps/extension/clip-time.test.mjs
@@ -1,5 +1,8 @@
 import { expect, test } from "bun:test";
 import { execFileSync } from "node:child_process";
+import { mkdtempSync, readFileSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
 
 // Separate processes ensure each runtime actually starts in the selected system timezone.
 test("clip metadata uses the system timezone across offsets, year boundaries and DST", () => {
@@ -8,8 +11,15 @@ test("clip metadata uses the system timezone across offsets, year boundaries and
     "Asia/Shanghai": ["2023-12-13 13:25:31", "2024-05-17 01:11:58", "2022-06-18 11:47:48", "2023-12-13 15:55:31", "2023-12-14 00:55:31", "2024-01-01 00:15:31", "2024-03-10 14:59:59", "2024-03-10 15:00:00"],
     "America/New_York": ["2023-12-13 00:25:31", "2024-05-16 13:11:58", "2022-06-17 23:47:48", "2023-12-13 02:55:31", "2023-12-13 11:55:31", "2023-12-31 11:15:31", "2024-03-10 01:59:59", "2024-03-10 03:00:00"],
   };
-  for (const [timezone, result] of Object.entries(expected)) {
-    const output = execFileSync(process.execPath, ["-e", `import { clipDateTimeText } from './src/clip-time.ts'; console.log(JSON.stringify(${JSON.stringify(values)}.map(clipDateTimeText)));`], { cwd: import.meta.dir, env: { ...process.env, TZ: timezone }, encoding: "utf8" });
-    expect(JSON.parse(output)).toEqual(result);
+  // Persist child results so this test does not depend on Bun test subprocess stdout capture.
+  const directory = mkdtempSync(join(tmpdir(), "edgeever-clip-time-"));
+  try {
+    for (const [timezone, result] of Object.entries(expected)) {
+      const outputPath = join(directory, "result.json");
+      execFileSync(process.execPath, ["-e", `import { writeFileSync } from 'node:fs'; import { clipDateTimeText } from './src/clip-time.ts'; writeFileSync(${JSON.stringify(outputPath)}, JSON.stringify(${JSON.stringify(values)}.map(clipDateTimeText)));`], { cwd: import.meta.dir, env: { ...process.env, TZ: timezone } });
+      expect(JSON.parse(readFileSync(outputPath, "utf8"))).toEqual(result);
+    }
+  } finally {
+    rmSync(directory, { recursive: true, force: true });
   }
 });