diff --git a/lib/index.js b/lib/index.js
index 52e9ea6..2de436c 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -31,11 +31,7 @@ const getPathInfo = (cmd, {
   if (isWindows) {
     const pathExtExe = optPathExt ||
       ['.EXE', '.CMD', '.BAT', '.COM'].join(optDelimiter)
-    const pathExt = pathExtExe.split(optDelimiter).reduce((acc, item) => {
-      acc.push(item)
-      acc.push(item.toLowerCase())
-      return acc
-    }, [])
+    const pathExt = pathExtExe.split(optDelimiter).flatMap((item) => [item, item.toLowerCase()])
     if (cmd.includes('.') && pathExt[0] !== '') {
       pathExt.unshift('')
     }