diff --git a/__tests__/exec.test.ts b/__tests__/exec.test.ts
index 1f83ce4..130f382 100644
--- a/__tests__/exec.test.ts
+++ b/__tests__/exec.test.ts
@@ -11,6 +11,11 @@ import * as io from '@actions/io'
 /* eslint-disable @typescript-eslint/unbound-method */
 
 const IS_WINDOWS = process.platform === 'win32'
+const SPAWN_WAIT_SCRIPT = path.join(
+  __dirname,
+  'scripts',
+  'spawn-wait-for-file.js'
+)
 
 let outstream: stream.Writable
 let errstream: stream.Writable
@@ -365,35 +370,20 @@ describe('@actions/exec', () => {
     fs.writeFileSync(semaphorePath, '')
 
     const nodePath = await io.which('node', true)
-    const scriptPath = path.join(__dirname, 'scripts', 'wait-for-file.js')
     const debugList: string[] = []
     const _testExecOptions = getExecOptions()
     _testExecOptions.delay = 500
-    _testExecOptions.windowsVerbatimArguments = true
     _testExecOptions.listeners = {
       debug: (data: string) => {
         debugList.push(data)
       }
     }
 
-    let exitCode: number
-    if (IS_WINDOWS) {
-      const toolName: string = await io.which('cmd.exe', true)
-      const args = [
-        '/D', // Disable execution of AutoRun commands from registry.
-        '/E:ON', // Enable command extensions. Note, command extensions are enabled by default, unless disabled via registry.
-        '/V:OFF', // Disable delayed environment expansion. Note, delayed environment expansion is disabled by default, unless enabled via registry.
-        '/S', // Will cause first and last quote after /C to be stripped.
-        '/C',
-        `"start "" /B "${nodePath}" "${scriptPath}" "file=${semaphorePath}""`
-      ]
-      exitCode = await exec.exec(`"${toolName}"`, args, _testExecOptions)
-    } else {
-      const toolName: string = await io.which('bash', true)
-      const args = ['-c', `node '${scriptPath}' 'file=${semaphorePath}' &`]
-
-      exitCode = await exec.exec(`"${toolName}"`, args, _testExecOptions)
-    }
+    const exitCode = await exec.exec(
+      `"${nodePath}"`,
+      [SPAWN_WAIT_SCRIPT, `file=${semaphorePath}`],
+      _testExecOptions
+    )
 
     expect(exitCode).toBe(0)
     expect(
@@ -411,36 +401,21 @@ describe('@actions/exec', () => {
     fs.writeFileSync(semaphorePath, '')
 
     const nodePath = await io.which('node', true)
-    const scriptPath = path.join(__dirname, 'scripts', 'wait-for-file.js')
     const debugList: string[] = []
     const _testExecOptions = getExecOptions()
     _testExecOptions.delay = 500
-    _testExecOptions.windowsVerbatimArguments = true
     _testExecOptions.listeners = {
       debug: (data: string) => {
         debugList.push(data)
       }
     }
 
-    let toolName: string
-    let args: string[]
-    if (IS_WINDOWS) {
-      toolName = await io.which('cmd.exe', true)
-      args = [
-        '/D', // Disable execution of AutoRun commands from registry.
-        '/E:ON', // Enable command extensions. Note, command extensions are enabled by default, unless disabled via registry.
-        '/V:OFF', // Disable delayed environment expansion. Note, delayed environment expansion is disabled by default, unless enabled via registry.
-        '/S', // Will cause first and last quote after /C to be stripped.
-        '/C',
-        `"start "" /B "${nodePath}" "${scriptPath}" "file=${semaphorePath}"" & exit /b 123`
-      ]
-    } else {
-      toolName = await io.which('bash', true)
-      args = ['-c', `node '${scriptPath}' 'file=${semaphorePath}' & exit 123`]
-    }
-
     await exec
-      .exec(`"${toolName}"`, args, _testExecOptions)
+      .exec(
+        `"${nodePath}"`,
+        [SPAWN_WAIT_SCRIPT, `file=${semaphorePath}`, 'exitCode=123'],
+        _testExecOptions
+      )
       .then(() => {
         throw new Error('Should not have succeeded')
       })
@@ -465,40 +440,22 @@ describe('@actions/exec', () => {
     fs.writeFileSync(semaphorePath, '')
 
     const nodePath = await io.which('node', true)
-    const scriptPath = path.join(__dirname, 'scripts', 'wait-for-file.js')
     const debugList: string[] = []
     const _testExecOptions = getExecOptions()
     _testExecOptions.delay = 500
     _testExecOptions.failOnStdErr = true
-    _testExecOptions.windowsVerbatimArguments = true
     _testExecOptions.listeners = {
       debug: (data: string) => {
         debugList.push(data)
       }
     }
 
-    let toolName: string
-    let args: string[]
-    if (IS_WINDOWS) {
-      toolName = await io.which('cmd.exe', true)
-      args = [
-        '/D', // Disable execution of AutoRun commands from registry.
-        '/E:ON', // Enable command extensions. Note, command extensions are enabled by default, unless disabled via registry.
-        '/V:OFF', // Disable delayed environment expansion. Note, delayed environment expansion is disabled by default, unless enabled via registry.
-        '/S', // Will cause first and last quote after /C to be stripped.
-        '/C',
-        `"start "" /B "${nodePath}" "${scriptPath}" "file=${semaphorePath}"" & echo hi 1>&2`
-      ]
-    } else {
-      toolName = await io.which('bash', true)
-      args = [
-        '-c',
-        `node '${scriptPath}' 'file=${semaphorePath}' & echo hi 1>&2`
-      ]
-    }
-
     await exec
-      .exec(`"${toolName}"`, args, _testExecOptions)
+      .exec(
+        `"${nodePath}"`,
+        [SPAWN_WAIT_SCRIPT, `file=${semaphorePath}`, 'stderr=true'],
+        _testExecOptions
+      )
       .then(() => {
         throw new Error('Should not have succeeded')
       })
@@ -515,7 +472,7 @@ describe('@actions/exec', () => {
     ).toBe(1)
 
     fs.unlinkSync(semaphorePath)
-  })
+  }, 10000)
 
   it('Exec roots relative tool path using unrooted options.cwd', async () => {
     let exitCode: number
diff --git a/__tests__/scripts/spawn-wait-for-file.js b/__tests__/scripts/spawn-wait-for-file.js
new file mode 100644
index 0000000..720b784
--- /dev/null
+++ b/__tests__/scripts/spawn-wait-for-file.js
@@ -0,0 +1,44 @@
+const childProcess = require('child_process')
+const path = require('path')
+
+// Parse args
+const args = {}
+for (const arg of process.argv.slice(2)) {
+  const idx = arg.indexOf('=')
+  if (idx !== -1) {
+    args[arg.slice(0, idx)] = arg.slice(idx + 1)
+  }
+}
+
+const filePath = args.file
+if (!filePath) {
+  throw new Error('file is not specified')
+}
+
+// Spawn wait-for-file.js with inherited stdio
+// This creates a grandchild process that holds the stdio handles open
+// after this process (the child) exits
+const waitScript = path.join(__dirname, 'wait-for-file.js')
+const isWindows = process.platform === 'win32'
+
+// On Windows, use detached:true to properly keep streams open
+// On Unix, detached:true also works and creates a new process group
+const child = childProcess.spawn(process.execPath, [waitScript, `file=${filePath}`], {
+  stdio: ['ignore', 'inherit', 'inherit'],
+  detached: true,
+  windowsHide: true
+})
+
+// Don't wait for child to exit
+child.unref()
+
+// Handle optional stderr output (must happen BEFORE we exit)
+if (args.stderr === 'true') {
+  process.stderr.write('hi')
+}
+
+// Small delay to ensure child has started and inherited handles
+setTimeout(() => {
+  const exitCode = args.exitCode ? parseInt(args.exitCode, 10) : 0
+  process.exit(exitCode)
+}, 50)