diff --git a/lib/util.js b/lib/util.js
index b59bae5067..1b168bfd94 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -505,6 +505,11 @@ function isFunction(arg) {
 }
 exports.isFunction = isFunction;
 
+function isPrimitive(arg) {
+  return !(arg instanceof Object);
+}
+exports.isPrimitive = isPrimitive;
+
 function isBuffer(arg) {
   return arg instanceof Buffer;
 }