diff --git a/modules/Expectation.js b/modules/Expectation.js
index bfbe4c9..1d9502b 100644
--- a/modules/Expectation.js
+++ b/modules/Expectation.js
@@ -1,5 +1,5 @@
-import deepEqual from 'deep-equal'
-import isRegExp from 'is-regexp'
+import isEqual from 'is-equal'
+import isRegExp from 'is-regex'
 import assert from './assert'
 import { isSpy } from './SpyUtils'
 import { functionThrows, arrayContains, stringContains, isArray, isFunction, isA } from './TestUtils'
@@ -65,7 +65,7 @@ class Expectation {
   toEqual(value, message) {
     try {
       assert(
-        deepEqual(this.actual, value),
+        isEqual(this.actual, value),
         (message || 'Expected %s to equal %s'),
         this.actual,
         value
@@ -83,7 +83,7 @@ class Expectation {
 
   toNotEqual(value, message) {
     assert(
-      !deepEqual(this.actual, value),
+      !isEqual(this.actual, value),
       (message || 'Expected %s to not equal %s'),
       this.actual,
       value
@@ -334,7 +334,7 @@ class Expectation {
 
     assert(
       spy.calls.some(function (call) {
-        return deepEqual(call.arguments, expectedArgs)
+        return isEqual(call.arguments, expectedArgs)
       }),
       'spy was never called with %s',
       expectedArgs
diff --git a/modules/TestUtils.js b/modules/TestUtils.js
index fcd1d60..730619f 100644
--- a/modules/TestUtils.js
+++ b/modules/TestUtils.js
@@ -1,5 +1,5 @@
-import deepEqual from 'deep-equal'
-import isRegExp from 'is-regexp'
+import isEqual from 'is-equal'
+import isRegExp from 'is-regex'
 
 /**
  * Returns true if the given function throws the given value
@@ -41,7 +41,7 @@ export function functionThrows(fn, context, args, value) {
  */
 export function arrayContains(array, value, comparator) {
   if (comparator == null)
-    comparator = deepEqual
+    comparator = isEqual
 
   return array.some(function (item) {
     return comparator(item, value) !== false
diff --git a/modules/__tests__/toEqual-test.js b/modules/__tests__/toEqual-test.js
index 8904351..6700634 100644
--- a/modules/__tests__/toEqual-test.js
+++ b/modules/__tests__/toEqual-test.js
@@ -8,6 +8,33 @@ describe('toEqual', function () {
     }).toThrow(/Expected 'actual' to equal 'expected'/)
   })
 
+  it('works when object has circular reference' , function () {
+    function circular() {
+      this.circularRef = this
+    }
+
+    const a = new circular()
+    const b = new circular()
+
+    expect(a).toEqual(b)
+  })
+
+  it('works with Map', function () {
+    const a = new Map()
+    a.set('key', 'value')
+
+    const b = new Map()
+    b.set('key', 'value')
+
+    expect(a).toEqual(b)
+  })
+
+  it('works with Set', function () {
+    const a = new Set('a')
+    const b = new Set('a')
+    expect(a).toEqual(b)
+  })
+
   it('shows diff', function () {
     try {
       expect('actual').toEqual('expected')
diff --git a/modules/__tests__/toNotEqual-test.js b/modules/__tests__/toNotEqual-test.js
new file mode 100644
index 0000000..20d49d1
--- /dev/null
+++ b/modules/__tests__/toNotEqual-test.js
@@ -0,0 +1,20 @@
+/*eslint-env mocha */
+import expect from '../index'
+
+describe('toNotEqual', function () {
+  it('works with Map', function () {
+    const a = new Map()
+    a.set('key', 'value')
+
+    const b = new Map()
+    b.set('key', 'another value')
+
+    expect(a).toNotEqual(b)
+  })
+
+  it('works with Set', function () {
+    const a = new Set('a')
+    const b = new Set('b')
+    expect(a).toNotEqual(b)
+  })
+})
diff --git a/package.json b/package.json
index 2744235..cd25a73 100644
--- a/package.json
+++ b/package.json
@@ -4,8 +4,8 @@
   "description": "Write better assertions",
   "main": "lib/index",
   "dependencies": {
-    "deep-equal": "^1.0.1",
-    "is-regexp": "^1.0.0",
+    "is-equal": "^1.3.0",
+    "is-regex": "^1.0.3",
     "object-inspect": "^1.0.2"
   },
   "devDependencies": {