diff --git a/index.js b/index.js
index 898ef09..c709843 100644
--- a/index.js
+++ b/index.js
@@ -180,14 +180,14 @@ function parse(code) {
   return elements;
 }
 
-async function recursiveReaddir(rpath, p, fileNames) {
+async function recursiveReaddir(rpath, p) {
   p = p || '';
-  fileNames = (fileNames || []).slice();
+  let fileNames = [];
   const files = await fs.readdir(rpath);
   for (const f of files) {
     const stat = await fs.lstat(path.join(rpath, f));
     if (stat.isDirectory() || stat.isSymbolicLink()) {
-      fileNames.push(...await recursiveReaddir(path.join(rpath, f), p + f + '/', fileNames));
+      fileNames.push(...await recursiveReaddir(path.join(rpath, f), p + f + '/'));
     } else {
       fileNames.push(p + f);
     }