diff --git a/index.js b/index.js
index d01e99e..a35b16d 100644
--- a/index.js
+++ b/index.js
@@ -29,7 +29,7 @@ const {
 } = require('./internal/validators');
 
 const {
-  kEmptyObject
+  kEmptyObject,
 } = require('./internal/util');
 
 const {
@@ -154,10 +154,9 @@ function storeOption(longOption, optionValue, options, values) {
  *         | boolean
  *         | string[]
  *         | boolean[]} optionValue - default value from option config
- * @param {object} options - option configs, from parseArgs({ options })
  * @param {object} values - option values returned in `values` by parseArgs
  */
-function storeDefaultOption(longOption, optionValue, options, values) {
+function storeDefaultOption(longOption, optionValue, values) {
   if (longOption === '__proto__') {
     return; // No. Just no.
   }
@@ -376,8 +375,9 @@ const parseArgs = (config = kEmptyObject) => {
 
   // Phase 3: fill in default values for missing args
   const defaultValueOptions = ArrayPrototypeFilter(
-    ObjectEntries(options), (option) => {
-      return useDefaultValueOption(option, result.values);
+    ObjectEntries(options), ({ 0: longOption,
+                               1: optionConfig }) => {
+      return useDefaultValueOption(longOption, optionConfig, result.values);
     });
 
   if (defaultValueOptions.length > 0) {
@@ -385,7 +385,6 @@ const parseArgs = (config = kEmptyObject) => {
                                                   1: optionConfig }) => {
       storeDefaultOption(longOption,
                          optionConfig.defaultValue,
-                         options,
                          result.values);
     });
 
diff --git a/internal/validators.js b/internal/validators.js
index 9bf79f3..b5ac4fb 100644
--- a/internal/validators.js
+++ b/internal/validators.js
@@ -1,5 +1,10 @@
 'use strict';
 
+// This file is a proxy of the original file located at:
+// https://github.com/nodejs/node/blob/main/lib/internal/validators.js
+// Every addition or modification to this file must be evaluated
+// during the PR review.
+
 const {
   ArrayIsArray,
   ArrayPrototypeIncludes,
diff --git a/test/default-values.js b/test/default-values.js
index a4a83a0..24ee094 100644
--- a/test/default-values.js
+++ b/test/default-values.js
@@ -166,7 +166,7 @@ test('proto as default value must be ignored', (t) => {
 });
 
 
-test('multiple as false should not expect an array', (t) => {
+test('multiple as false should expect a String and not an array', (t) => {
   const args = [];
   const options = { alpha: { type: 'string', multiple: false, defaultValue: 42 } };
   t.throws(() => {
diff --git a/utils.js b/utils.js
index 8b4dd95..e0e2178 100644
--- a/utils.js
+++ b/utils.js
@@ -174,12 +174,12 @@ function findLongOptionForShort(shortOption, options) {
  * Check if the given option includes a default value
  * and that option has not been set by the input args.
  *
- * @param {array} options - option configs entry, from parseArgs({ options })
+ * @param {string} longOption - long option name e.g. 'foo'
+ * @param {object} optionConfig - the option configuration properties
  * @param {object} values - option values returned in `values` by parseArgs
  */
-function useDefaultValueOption({ 0: longOption,
-                                 1: optionConfig }, values) {
-  return optionConfig.defaultValue !== undefined &&
+function useDefaultValueOption(longOption, optionConfig, values) {
+  return objectGetOwn(optionConfig, 'defaultValue') !== undefined &&
   values[longOption] === undefined;
 }