diff --git a/src/rules/type.js b/src/rules/type.js
index 74212e2..e289030 100644
--- a/src/rules/type.js
+++ b/src/rules/type.js
@@ -1,3 +1,3 @@
-export default (sample, expected) => {
-  return sample.constructor === expected;
-};
+export default (sample, expected) => (
+  typeof sample === 'undefined' || sample.constructor === expected
+);
diff --git a/test/rules/type.spec.js b/test/rules/type.spec.js
index 8171c0b..ebf829a 100644
--- a/test/rules/type.spec.js
+++ b/test/rules/type.spec.js
@@ -2,7 +2,6 @@ import { expect } from 'chai';
 import type from '../../src/rules/type';
 
 describe('type()', () => {
-
   it('Up & Running', () => {
     expect(typeof type).to.equal('function');
   });
@@ -11,23 +10,51 @@ describe('type()', () => {
     expect(type('hello', String)).to.equal(true);
   });
 
+  it('reject a {string} sample', () => {
+    expect(type(1980, String)).to.equal(false);
+  });
+
   it('accept a {number} sample', () => {
     expect(type(1980, Number)).to.equal(true);
   });
 
+  it('reject a {number} sample', () => {
+    expect(type('1980', Number)).to.equal(false);
+  });
+
   it('accept a {array} sample', () => {
     expect(type(['hello', 'world'], Array)).to.equal(true);
   });
 
+  it('reject a {array} sample', () => {
+    expect(type({ hello: 'world' }, Array)).to.equal(false);
+  });
+
   it('accept a {object} sample', () => {
     expect(type({ hello: 'world' }, Object)).to.equal(true);
   });
 
+  it('reject a {object} sample', () => {
+    expect(type(['hello', 'world'], Object)).to.equal(false);
+  });
+
   it('accept a {date} sample', () => {
     expect(type(new Date(1980), Date)).to.equal(true);
   });
 
+  it('reject a {date} sample', () => {
+    expect(type(true, Date)).to.equal(false);
+  });
+
   it('accept a {boolean} sample', () => {
     expect(type(true, Boolean)).to.equal(true);
   });
+
+  it('reject a {boolean} sample', () => {
+    expect(type(new Date(1980), Boolean)).to.equal(false);
+  });
+
+  it('accept a {undefined} sample', () => {
+    expect(type(undefined, String)).to.equal(true);
+  });
 });