diff --git a/oclif/package.json b/oclif/package.json
index e005d82..5bf412e 100644
--- a/oclif/package.json
+++ b/oclif/package.json
@@ -25,6 +25,7 @@
     "esbuild-register": "^3.3.2",
     "npm-run-all": "^4.1.5",
     "oclif": "^3.0.0",
+    "stdout-stderr": "^0.1.13",
     "tsup": "^5.12.5",
     "typescript": "^4.6.3",
     "vitest": "^0.9.3"
diff --git a/oclif/tests/commands/hello/index.test.ts b/oclif/tests/commands/hello/index.test.ts
index d192bfd..2b8abba 100644
--- a/oclif/tests/commands/hello/index.test.ts
+++ b/oclif/tests/commands/hello/index.test.ts
@@ -1,8 +1,8 @@
 import { test, expect } from "vitest";
-import run from "../../run";
+import { stdout } from "stdout-stderr";
 import Hello from "../../../src/commands/hello/index";
 
 test("hello", async () => {
-  const res = await run(() => Hello.run(["friend", "--from=oclif"]));
-  expect(res).toContain("hello friend from oclif!");
+  await Hello.run(["friend", "--from=oclif"]);
+  expect(stdout.output).toContain("hello friend from oclif!");
 });
diff --git a/oclif/tests/commands/hello/world.test.ts b/oclif/tests/commands/hello/world.test.ts
index d17660e..0576a2a 100644
--- a/oclif/tests/commands/hello/world.test.ts
+++ b/oclif/tests/commands/hello/world.test.ts
@@ -1,13 +1,8 @@
-import {  test, expect } from "vitest";
-import run from "../../run";
+import { test, expect } from "vitest";
+import { stdout } from "stdout-stderr";
 import World from "../../../src/commands/hello/world";
 
 test("hello world", async () => {
-  const res = await run(() => World.run());
-  expect(res).toContain("hello world!");
-});
-
-test("hello world", async () => {
-  const res = await run(() => World.run());
-  expect(res).toContain("hello world!");
+  await World.run();
+  expect(stdout.output).toContain("hello world!");
 });
diff --git a/oclif/tests/run.ts b/oclif/tests/run.ts
deleted file mode 100644
index fe81da0..0000000
--- a/oclif/tests/run.ts
+++ /dev/null
@@ -1,19 +0,0 @@
-import { vi } from "vitest";
-
-/**
- * 標準出力のテストのためのヘルパー
- * @param proc 実行する関数
- * @return 標準出力の結果
- */
-async function run(proc: () => PromiseLike<void>): Promise<string> {
-  const out: string[] = [];
-  const stdout = vi.spyOn(process.stdout, "write").mockImplementation((val) => {
-    out.push(val as string);
-    return true;
-  });
-  await proc();
-  stdout.mockRestore();
-  return out.join("");
-}
-
-export default run;
diff --git a/oclif/tests/setup.ts b/oclif/tests/setup.ts
new file mode 100644
index 0000000..07aa12f
--- /dev/null
+++ b/oclif/tests/setup.ts
@@ -0,0 +1,12 @@
+import { afterEach, beforeEach } from "vitest";
+import { stdout, stderr } from "stdout-stderr";
+
+beforeEach(() => {
+  stdout.start();
+  stderr.start();
+});
+
+afterEach(() => {
+  stdout.stop();
+  stderr.stop();
+});
diff --git a/oclif/vitest.config.ts b/oclif/vitest.config.ts
new file mode 100644
index 0000000..21ee1ff
--- /dev/null
+++ b/oclif/vitest.config.ts
@@ -0,0 +1,7 @@
+import { defineConfig } from "vite";
+
+export default defineConfig({
+  test: {
+    setupFiles: "tests/setup.ts",
+  },
+});
diff --git a/oclif/yarn.lock b/oclif/yarn.lock
index 4f160dc..7adeda1 100644
--- a/oclif/yarn.lock
+++ b/oclif/yarn.lock
@@ -3615,6 +3615,14 @@ ssri@^9.0.0:
   dependencies:
     minipass "^3.1.1"
 
+stdout-stderr@^0.1.13:
+  version "0.1.13"
+  resolved "https://registry.yarnpkg.com/stdout-stderr/-/stdout-stderr-0.1.13.tgz#54e3450f3d4c54086a49c0c7f8786a44d1844b6f"
+  integrity sha512-Xnt9/HHHYfjZ7NeQLvuQDyL1LnbsbddgMFKCuaQKwGCdJm8LnstZIXop+uOY36UR1UXXoHXfMbC1KlVdVd2JLA==
+  dependencies:
+    debug "^4.1.1"
+    strip-ansi "^6.0.0"
+
 string-width@^1.0.1:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/string-width/-/string-width-1.0.2.tgz#118bdf5b8cdc51a2a7e70d211e07e2b0b9b107d3"