diff --git a/lib/fs.js b/lib/fs.js
index 27614e5cf1febc..12ba9b8dba790f 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -56,8 +56,8 @@ function getOptions(options, defaultOptions) {
   return options;
 }
 
-function copyObject(source, target) {
-  target = arguments.length >= 2 ? target : {};
+function copyObject(source) {
+  const target = {};
   for (const key in source)
     target[key] = source[key];
   return target;