diff --git a/index.js b/index.js
index 7b238dd..ff2599a 100644
--- a/index.js
+++ b/index.js
@@ -91,13 +91,11 @@ module.exports = function requireDir(dir, opts) {
             continue;
         }
 
-        // Node v8+ uses "clean" objects w/o hasOwnProperty for require
-        var hasExt = require.extensions.hasOwnProperty || function(ext) { return require.extensions[ext]; };
-
         // otherwise, go through and try each require.extension key!
         for (ext in require.extensions) {
+            // Node v8+ uses "clean" objects w/o hasOwnProperty for require
             // again protect against enumerable object prototype extensions:
-            if (!hasExt(ext)) {
+            if (!Object.prototype.hasOwnProperty.call(require.extensions, ext)) {
                 continue;
             }