diff --git a/package.json b/package.json
index 05d2007d..a4179526 100644
--- a/package.json
+++ b/package.json
@@ -45,7 +45,7 @@
     "shx": "^0.4.0",
     "sinon": "^18",
     "ts-node": "^10.9.2",
-    "typescript": "^5.7.3"
+    "typescript": "^6"
   },
   "engines": {
     "node": ">=18.0.0"
diff --git a/test/.DS_Store b/test/.DS_Store
new file mode 100644
index 00000000..723f762b
Binary files /dev/null and b/test/.DS_Store differ
diff --git a/test/spawn.test.ts b/test/spawn.test.ts
index 97999d43..7754ca19 100644
--- a/test/spawn.test.ts
+++ b/test/spawn.test.ts
@@ -1,7 +1,7 @@
 import {expect} from 'chai'
 import {chmodSync, mkdirSync, mkdtempSync, readFileSync, rmSync, symlinkSync, writeFileSync} from 'node:fs'
 import {tmpdir} from 'node:os'
-import {dirname, join} from 'node:path'
+import path from 'node:path'
 import {fileURLToPath} from 'node:url'
 
 import {spawn} from '../src/spawn.js'
@@ -10,7 +10,7 @@ describe('spawn', () => {
   let tempDir: string
 
   beforeEach(() => {
-    tempDir = mkdtempSync(join(tmpdir(), 'spawn-test-'))
+    tempDir = mkdtempSync(path.join(tmpdir(), 'spawn-test-'))
   })
 
   afterEach(() => {
@@ -18,7 +18,7 @@ describe('spawn', () => {
   })
 
   it('should invoke .js module paths via process.execPath', async () => {
-    const script = join(tempDir, 'test-script.js')
+    const script = path.join(tempDir, 'test-script.js')
     writeFileSync(script, '#!/usr/bin/env nonexistent-node-binary\nconsole.log("spawned-ok")\n')
     chmodSync(script, '755')
 
@@ -28,7 +28,7 @@ describe('spawn', () => {
   })
 
   it('should pass args after the .js module path', async () => {
-    const script = join(tempDir, 'echo-args.js')
+    const script = path.join(tempDir, 'echo-args.js')
     writeFileSync(script, 'console.log(JSON.stringify(process.argv.slice(2)))\n')
     chmodSync(script, '755')
 
@@ -38,9 +38,9 @@ describe('spawn', () => {
   })
 
   it('should handle .js module paths with spaces in the path', async () => {
-    const dir = join(tempDir, 'dir with spaces')
+    const dir = path.join(tempDir, 'dir with spaces')
     mkdirSync(dir)
-    const script = join(dir, 'my script.js')
+    const script = path.join(dir, 'my script.js')
     writeFileSync(script, 'console.log("spaces-ok")\n')
     chmodSync(script, '755')
 
@@ -51,12 +51,12 @@ describe('spawn', () => {
 
   it('should handle process.execPath containing spaces', async function () {
     if (process.platform === 'win32') return this.skip()
-    const nodeDir = join(tempDir, 'path with spaces', 'bin')
+    const nodeDir = path.join(tempDir, 'path with spaces', 'bin')
     mkdirSync(nodeDir, {recursive: true})
-    const nodeLink = join(nodeDir, 'node')
+    const nodeLink = path.join(nodeDir, 'node')
     symlinkSync(process.execPath, nodeLink)
 
-    const script = join(tempDir, 'exec-path-test.js')
+    const script = path.join(tempDir, 'exec-path-test.js')
     writeFileSync(script, 'console.log("execpath-ok")\n')
     chmodSync(script, '755')
 
@@ -71,12 +71,16 @@ describe('spawn', () => {
   })
 
   it('must use windowsVerbatimArguments to prevent argument injection (security)', () => {
-    const spawnSrc = readFileSync(join(dirname(fileURLToPath(import.meta.url)), '..', 'src', 'spawn.ts'), 'utf8')
+    const spawnSrc = readFileSync(
+      // eslint-disable-next-line unicorn/max-nested-calls
+      path.join(path.dirname(fileURLToPath(import.meta.url)), '..', 'src', 'spawn.ts'),
+      'utf8',
+    )
     expect(spawnSrc).to.include('windowsVerbatimArguments: true')
   })
 
   it('should not interpret shell metacharacters in arguments', async () => {
-    const script = join(tempDir, 'echo-args.js')
+    const script = path.join(tempDir, 'echo-args.js')
     writeFileSync(script, 'console.log(JSON.stringify(process.argv.slice(2)))\n')
     chmodSync(script, '755')
 
@@ -94,7 +98,7 @@ describe('spawn', () => {
 
   it('should not modify non-.js module paths', async function () {
     if (process.platform === 'win32') return this.skip()
-    const script = join(tempDir, 'test-bin')
+    const script = path.join(tempDir, 'test-bin')
     writeFileSync(script, `#!/usr/bin/env bash\necho "bin-ok"\n`)
     chmodSync(script, '755')
 
diff --git a/test/tsconfig.json b/test/tsconfig.json
index b9fdd635..01d9c8fb 100644
--- a/test/tsconfig.json
+++ b/test/tsconfig.json
@@ -1,4 +1,7 @@
 {
   "extends": "../tsconfig",
-  "include": ["./**/*", "../src/**/*"]
+  "include": ["./**/*", "../src/**/*"],
+  "compilerOptions": {
+    "rootDir": "../"
+  }
 }
diff --git a/tsconfig.json b/tsconfig.json
index 26c7a548..f51dd9af 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -5,7 +5,8 @@
     "module": "Node16",
     "outDir": "./lib",
     "pretty": true,
-    "rootDirs": ["./src"],
+    "rootDir": "./src",
+    "types": ["node", "mocha"],
     "strict": true,
     "target": "ES2022",
     "moduleResolution": "Node16",
diff --git a/yarn.lock b/yarn.lock
index 7f7608ae..81af3b4c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -6105,10 +6105,10 @@ typescript-eslint@^8.64.0, typescript-eslint@^8.66.0:
     "@typescript-eslint/typescript-estree" "8.67.0"
     "@typescript-eslint/utils" "8.67.0"
 
-typescript@^5.7.3:
-  version "5.9.3"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-5.9.3.tgz#5b4f59e15310ab17a216f5d6cf53ee476ede670f"
-  integrity sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==
+typescript@^6:
+  version "6.0.3"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-6.0.3.tgz#90251dc007916e972786cb94d74d15b185577d21"
+  integrity sha512-y2TvuxSZPDyQakkFRPZHKFm+KKVqIisdg9/CZwm9ftvKXLP8NRWj38/ODjNbr43SsoXqNuAisEf1GdCxqWcdBw==
 
 undici-types@~5.26.4:
   version "5.26.5"