diff --git a/lib/sys.js b/lib/sys.js
index 0c027f5d32a..ca97a884959 100644
--- a/lib/sys.js
+++ b/lib/sys.js
@@ -106,13 +106,8 @@ exports.inspect = function (obj, showHidden, depth, colors) {
     }
 
     // Look up the keys of the object.
-    if (showHidden) {
-      var keys = Object.getOwnPropertyNames(value).map(function (key) { return '' + key; });
-    } else {
-      var keys = Object.keys(value);
-    }
-
     var visible_keys = Object.keys(value);
+    var keys = showHidden ? Object.getOwnPropertyNames(value) : visible_keys;
 
     // Functions without properties can be shortcutted.
     if (typeof value === 'function' && keys.length === 0) {