diff --git a/tests/index.js b/tests/index.js
deleted file mode 100644
index 89e3bfc..0000000
--- a/tests/index.js
+++ /dev/null
@@ -1,45 +0,0 @@
-import {assert} from 'chai';
-import {machineId, machineIdSync} from '../dist/index';
-
-let {platform} = process,
-    originalPattern = {
-        darwin: /^[0-9,A-z]{8}-[0-9,A-z]{4}-[0-9,A-z]{4}-[0-9,A-z]{4}-[0-9,A-z]{12}$/,
-        win32: /^[0-9,A-z]{8}-[0-9,A-z]{4}-[0-9,A-z]{4}-[0-9,A-z]{4}-[0-9,A-z]{12}$/,
-        linux: /^[0-9,A-z]{32}$/,
-        freebsd: /^[0-9,A-z]{8}-[0-9,A-z]{4}-[0-9,A-z]{4}-[0-9,A-z]{4}-[0-9,A-z]{12}$/
-    },
-    hashPattern = /^[0-9,A-z]{64}$/;
-
-describe('Async call: machineId({original: true})', function() {
-    it('should return original unique id', async () => {
-        let id = await machineId({original: true});
-        assert.match(id, originalPattern[platform]);
-    });
-});
-
-describe('Sync call: machineIdSync({original: true})', function() {
-    it('should return original unique id', () => {
-        assert.match(machineIdSync({original: true}), originalPattern[platform]);
-    });
-});
-
-describe('Async call: machineId()', function() {
-    it('should return unique sha256-hash', async () => {
-        let id = await machineId();
-        assert.match(id, hashPattern);
-    });
-});
-
-describe('Sync call: machineIdSync()', function() {
-    it('should return unique sha256-hash', () => {
-        assert.match(machineIdSync(), hashPattern);
-    });
-});
-
-describe('CommonJS imports', function () {
-    it('should return function machineIdSync, machineId', function () {
-        let __module__ = require('../dist/index');
-        assert.isFunction(__module__.machineId);
-        assert.isFunction(__module__.machineIdSync);
-    });
-});
diff --git a/tests/machine-id.test.js b/tests/machine-id.test.js
new file mode 100644
index 0000000..355c284
--- /dev/null
+++ b/tests/machine-id.test.js
@@ -0,0 +1,47 @@
+const assert = require('assert');
+const {test} = require('node:test');
+const {createHash} = require('crypto');
+const {machineId, machineIdSync} = require('../dist/index');
+
+const platform = process.platform;
+const originalPattern = {
+  darwin: /^[0-9A-Za-z]{8}-[0-9A-Za-z]{4}-[0-9A-Za-z]{4}-[0-9A-Za-z]{4}-[0-9A-Za-z]{12}$/,
+  win32: /^[0-9A-Za-z]{8}-[0-9A-Za-z]{4}-[0-9A-Za-z]{4}-[0-9A-Za-z]{4}-[0-9A-Za-z]{12}$/,
+  linux: /^[0-9A-Za-z]{32}$/,
+  freebsd: /^[0-9A-Za-z]{8}-[0-9A-Za-z]{4}-[0-9A-Za-z]{4}-[0-9A-Za-z]{4}-[0-9A-Za-z]{12}$/
+};
+const hashPattern = /^[0-9A-Za-z]{64}$/;
+
+test('machineIdSync(true) returns original unique id', () => {
+  const id = machineIdSync(true);
+  assert.match(id, originalPattern[platform]);
+});
+
+test('machineId(true) returns the same original id', async () => {
+  const asyncId = await machineId(true);
+  const syncId = machineIdSync(true);
+  assert.strictEqual(asyncId, syncId);
+  assert.match(asyncId, originalPattern[platform]);
+});
+
+test('machineIdSync() returns sha256 hash of the original id', () => {
+  const original = machineIdSync(true);
+  const expected = createHash('sha256').update(original).digest('hex');
+  const hashed = machineIdSync();
+  assert.match(hashed, hashPattern);
+  assert.strictEqual(hashed, expected);
+});
+
+test('machineId() returns sha256 hash of the original id', async () => {
+  const original = await machineId(true);
+  const expected = createHash('sha256').update(original).digest('hex');
+  const hashed = await machineId();
+  assert.match(hashed, hashPattern);
+  assert.strictEqual(hashed, expected);
+});
+
+test('CommonJS import exposes machineId functions', () => {
+  const mod = require('../dist/index');
+  assert.strictEqual(typeof mod.machineId, 'function');
+  assert.strictEqual(typeof mod.machineIdSync, 'function');
+});