diff --git a/lib/util.js b/lib/util.js
index 1a2f3f34835899..236adf35b87eab 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -6,7 +6,6 @@ const internalUtil = require('internal/util');
 const binding = process.binding('util');
 
 const isError = internalUtil.isError;
-const objectToString = internalUtil.objectToString;
 
 var Debug;
 
@@ -305,7 +304,7 @@ function formatValue(ctx, value, recurseTimes) {
     braces = ['[', ']'];
     empty = value.length === 0;
     formatter = formatArray;
-  } else if (objectToString(value) === '[object Set]') {
+  } else if (binding.isSet(value)) {
     braces = ['{', '}'];
     // With `showHidden`, `length` will display as a hidden property for
     // arrays. For consistency's sake, do the same for `size`, even though this
@@ -314,7 +313,7 @@ function formatValue(ctx, value, recurseTimes) {
       keys.unshift('size');
     empty = value.size === 0;
     formatter = formatSet;
-  } else if (objectToString(value) === '[object Map]') {
+  } else if (binding.isMap(value)) {
     braces = ['{', '}'];
     // Ditto.
     if (ctx.showHidden)
@@ -673,7 +672,7 @@ function isUndefined(arg) {
 exports.isUndefined = isUndefined;
 
 function isRegExp(re) {
-  return objectToString(re) === '[object RegExp]';
+  return binding.isRegExp(re);
 }
 exports.isRegExp = isRegExp;
 
@@ -683,7 +682,7 @@ function isObject(arg) {
 exports.isObject = isObject;
 
 function isDate(d) {
-  return objectToString(d) === '[object Date]';
+  return binding.isDate(d);
 }
 exports.isDate = isDate;
 
diff --git a/src/node_util.cc b/src/node_util.cc
index a520b8d5f354ac..ea800ff339a36f 100644
--- a/src/node_util.cc
+++ b/src/node_util.cc
@@ -13,12 +13,37 @@ using v8::Object;
 using v8::String;
 using v8::Value;
 
+
+static void IsRegExp(const FunctionCallbackInfo<Value>& args) {
+  CHECK_EQ(1, args.Length());
+  args.GetReturnValue().Set(args[0]->IsRegExp());
+}
+
+
+static void IsDate(const FunctionCallbackInfo<Value>& args) {
+  CHECK_EQ(1, args.Length());
+  args.GetReturnValue().Set(args[0]->IsDate());
+}
+
+
+static void IsMap(const FunctionCallbackInfo<Value>& args) {
+  CHECK_EQ(1, args.Length());
+  args.GetReturnValue().Set(args[0]->IsMap());
+}
+
+
 static void IsMapIterator(const FunctionCallbackInfo<Value>& args) {
   CHECK_EQ(1, args.Length());
   args.GetReturnValue().Set(args[0]->IsMapIterator());
 }
 
 
+static void IsSet(const FunctionCallbackInfo<Value>& args) {
+  CHECK_EQ(1, args.Length());
+  args.GetReturnValue().Set(args[0]->IsSet());
+}
+
+
 static void IsSetIterator(const FunctionCallbackInfo<Value>& args) {
   CHECK_EQ(1, args.Length());
   args.GetReturnValue().Set(args[0]->IsSetIterator());
@@ -50,7 +75,11 @@ void Initialize(Local<Object> target,
                 Local<Value> unused,
                 Local<Context> context) {
   Environment* env = Environment::GetCurrent(context);
+  env->SetMethod(target, "isRegExp", IsRegExp);
+  env->SetMethod(target, "isDate", IsDate);
+  env->SetMethod(target, "isMap", IsMap);
   env->SetMethod(target, "isMapIterator", IsMapIterator);
+  env->SetMethod(target, "isSet", IsSet);
   env->SetMethod(target, "isSetIterator", IsSetIterator);
   env->SetMethod(target, "isPromise", IsPromise);
   env->SetMethod(target, "getHiddenValue", GetHiddenValue);