diff --git a/.eslintrc b/.eslintrc
index d48d448..1afa2a8 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -1,5 +1,4 @@
 {
-  "extends": ["airbnb"],
   "parser": "@typescript-eslint/parser",
   "plugins": ["@typescript-eslint"],
   "settings": {
diff --git a/__tests__/__helpers__/testSuites.js b/__tests__/__helpers__/testSuites.js
index 8a9bc6d..f743d5f 100644
--- a/__tests__/__helpers__/testSuites.js
+++ b/__tests__/__helpers__/testSuites.js
@@ -49,6 +49,20 @@ module.exports = [
         value1: -Infinity,
         value2: Infinity,
       },
+      {
+        deepEqual: true,
+        description: 'equal number objects',
+        shallowEqual: true,
+        value1: new Number(1),
+        value2: new Number(1),
+      },
+      {
+        deepEqual: false,
+        description: 'not equal number objects',
+        shallowEqual: false,
+        value1: new Number(1),
+        value2: new Number(2),
+      },
       {
         deepEqual: false,
         description: 'number and array are not equal',
@@ -84,6 +98,20 @@ module.exports = [
         value1: 'a',
         value2: 'b',
       },
+      {
+        deepEqual: true,
+        description: 'equal string objects',
+        shallowEqual: true,
+        value1: new String('foo'),
+        value2: new String('foo'),
+      },
+      {
+        deepEqual: false,
+        description: 'not equal string objects',
+        shallowEqual: false,
+        value1: new String('foo'),
+        value2: new String('bar'),
+      },
       {
         deepEqual: false,
         description: 'empty string and null are not equal',
@@ -112,6 +140,20 @@ module.exports = [
         value1: false,
         value2: false,
       },
+      {
+        deepEqual: true,
+        description: 'equal boolean objects (true)',
+        shallowEqual: true,
+        value1: new Boolean(true),
+        value2: new Boolean(true),
+      },
+      {
+        deepEqual: true,
+        description: 'equal boolean objects (false)',
+        shallowEqual: true,
+        value1: new Boolean(false),
+        value2: new Boolean(false),
+      },
       {
         deepEqual: false,
         description: 'not equal booleans',
@@ -119,6 +161,13 @@ module.exports = [
         value1: true,
         value2: false,
       },
+      {
+        deepEqual: false,
+        description: 'not equal boolean objects',
+        shallowEqual: false,
+        value1: new Boolean(true),
+        value2: new Boolean(false),
+      },
       {
         deepEqual: false,
         description: '1 and true are not equal',
diff --git a/src/comparator.ts b/src/comparator.ts
index e436c46..162876e 100644
--- a/src/comparator.ts
+++ b/src/comparator.ts
@@ -1,6 +1,4 @@
 import {
-  EqualityComparator,
-  InternalEqualityComparator,
   areArraysEqual,
   areMapsEqual,
   areObjectsEqual,
@@ -11,17 +9,33 @@ import {
   sameValueZeroEqual,
 } from './utils';
 
+import type { EqualityComparator, InternalEqualityComparator } from './types';
+
 const HAS_MAP_SUPPORT = typeof Map === 'function';
 const HAS_SET_SUPPORT = typeof Set === 'function';
 
-export type EqualityComparatorCreator = (fn: EqualityComparator) => InternalEqualityComparator;
+const { valueOf } = Object.prototype;
+
+export type EqualityComparatorCreator = (
+  fn: EqualityComparator,
+) => InternalEqualityComparator;
 
-export function createComparator(createIsEqual?: EqualityComparatorCreator): EqualityComparator {
+export function createComparator(
+  createIsEqual?: EqualityComparatorCreator,
+): EqualityComparator {
   const isEqual: InternalEqualityComparator =
     /* eslint-disable no-use-before-define */
     typeof createIsEqual === 'function'
       ? createIsEqual(comparator)
-      : (a: any, b: any, indexOrKeyA: any, indexOrKeyB: any, parentA: any, parentB: any, meta: any) => comparator(a, b, meta);
+      : (
+          a: any,
+          b: any,
+          indexOrKeyA: any,
+          indexOrKeyB: any,
+          parentA: any,
+          parentB: any,
+          meta: any,
+        ) => comparator(a, b, meta);
   /* eslint-enable */
 
   /**
@@ -87,6 +101,10 @@ export function createComparator(createIsEqual?: EqualityComparatorCreator): Equ
         }
       }
 
+      if (a.valueOf !== valueOf || b.valueOf !== valueOf) {
+        return sameValueZeroEqual(a.valueOf(), b.valueOf());
+      }
+
       return areObjectsEqual(a, b, isEqual, meta);
     }
 
diff --git a/src/types.ts b/src/types.ts
new file mode 100644
index 0000000..8e31e6b
--- /dev/null
+++ b/src/types.ts
@@ -0,0 +1,15 @@
+export type InternalEqualityComparator = (
+  objectA: any,
+  objectB: any,
+  indexOrKeyA: any,
+  indexOrKeyB: any,
+  parentA: any,
+  parentB: any,
+  meta: any,
+) => boolean;
+
+export type EqualityComparator = <A, B, Meta>(
+  objectA: A,
+  objectB: B,
+  meta?: Meta,
+) => boolean;
diff --git a/src/utils.ts b/src/utils.ts
index d48123f..3d05aef 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,28 +1,14 @@
-const HAS_WEAKSET_SUPPORT = typeof WeakSet === 'function';
+import type { EqualityComparator, InternalEqualityComparator } from './types';
 
 const { keys } = Object;
 
+const HAS_WEAKSET_SUPPORT = typeof WeakSet === 'function';
+
 type Cache = {
   add: (value: any) => void;
   has: (value: any) => boolean;
 };
 
-export type InternalEqualityComparator = (
-  objectA: any,
-  objectB: any,
-  indexOrKeyA: any,
-  indexOrKeyB: any,
-  parentA: any,
-  parentB: any,
-  meta: any,
-) => boolean;
-
-export type EqualityComparator = <A, B, Meta>(
-  objectA: A,
-  objectB: B,
-  meta?: Meta,
-) => boolean;
-
 /**
  * are the values passed strictly equal or both NaN
  *