diff --git a/lib/internal/util.js b/lib/internal/util.js
index 7af06351c91406..652e75504060aa 100644
--- a/lib/internal/util.js
+++ b/lib/internal/util.js
@@ -267,10 +267,9 @@ function promisify(original) {
     if (typeof fn !== 'function') {
       throw new ERR_INVALID_ARG_TYPE('util.promisify.custom', 'Function', fn);
     }
-    Object.defineProperty(fn, kCustomPromisifiedSymbol, {
+    return Object.defineProperty(fn, kCustomPromisifiedSymbol, {
       value: fn, enumerable: false, writable: false, configurable: true
     });
-    return fn;
   }
 
   // Names to create an object from in case the callback receives multiple