diff --git a/lib/fs.js b/lib/fs.js
index c30de937c2afed..c1d8db9f8cb6ee 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -200,10 +200,11 @@ fs.Stats.prototype.isSocket = function() {
 };
 
 // Don't allow mode to accidentally be overwritten.
-['F_OK', 'R_OK', 'W_OK', 'X_OK'].forEach(function(key) {
-  Object.defineProperty(fs, key, {
-    enumerable: true, value: constants[key] || 0, writable: false
-  });
+Object.defineProperties(fs, {
+  F_OK: {enumerable: true, value: constants.F_OK || 0},
+  R_OK: {enumerable: true, value: constants.R_OK || 0},
+  W_OK: {enumerable: true, value: constants.W_OK || 0},
+  X_OK: {enumerable: true, value: constants.X_OK || 0},
 });
 
 function handleError(val, callback) {