diff --git a/chai-as-promised/chai-as-promised-tests.ts b/chai-as-promised/chai-as-promised-tests.ts
index 95a4335173..0b747d2c4c 100644
--- a/chai-as-promised/chai-as-promised-tests.ts
+++ b/chai-as-promised/chai-as-promised-tests.ts
@@ -1,23 +1,54 @@
 /// <reference path="chai-as-promised.d.ts" />
+/// <reference path="../promises-a-plus/promises-a-plus.d.ts" />
+/// <reference path="../q/Q.d.ts" />
 
 import chai = require('chai');
 import chaiAsPromised = require('chai-as-promised');
+import Q = require('q');
 
 chai.use(chaiAsPromised);
 
 // ReSharper disable WrongExpressionStatement
-var promise: any;
-chai.expect(promise).to.eventually.equal(3);
-chai.expect(promise).to.become(3);
-chai.expect(promise).to.be.fulfilled;
-chai.expect(promise).to.be.rejected;
-chai.expect(promise).to.be.rejectedWith(Error);
-chai.expect(promise).to.notify(() => console.log('done'));
+// BDD API (expect)
+var thenableNum: PromisesAPlus.Thenable<number>;
+thenableNum = chai.expect(thenableNum).to.eventually.equal(3);
+thenableNum = chai.expect(thenableNum).to.eventually.have.property('foo');
+thenableNum = chai.expect(thenableNum).to.become(3);
+thenableNum = chai.expect(thenableNum).to.be.fulfilled;
+thenableNum = chai.expect(thenableNum).to.be.rejected;
+thenableNum = chai.expect(thenableNum).to.be.rejectedWith(Error);
+thenableNum = chai.expect(thenableNum).to.notify(() => console.log('done'));
 
-chai.assert.eventually.equal(promise, 4, 'Message');
-chai.assert.isFulfilled(promise, "optional message");
-chai.assert.becomes(promise, "foo", "optional message");
-chai.assert.doesNotBecome(promise, "foo", "optional message");
-chai.assert.isRejected(promise, "optional message");
-chai.assert.isRejected(promise, Error, "optional message");
-chai.assert.isRejected(promise, /error message matcher/, "optional message");
+// BDD API (should)
+thenableNum = thenableNum.should.be.fulfilled;
+thenableNum = thenableNum.should.eventually.deep.equal(3);
+thenableNum = thenableNum.should.become(3);
+thenableNum = thenableNum.should.be.rejected;
+thenableNum = thenableNum.should.be.rejectedWith(Error);
+thenableNum = thenableNum.should.eventually.equal(3).notify(() => console.log('done'));
+thenableNum = thenableNum.should.be.fulfilled.and.notify(() => console.log('done'));
+
+// Complex examples on https://github.com/domenic/chai-as-promised#working-with-non-promisefriendly-test-runners
+thenableNum.should.be.fulfilled.then(function () {
+  thenableNum.should.equal("after");
+}).should.notify(() => console.log('done'));
+
+Q.all([
+    thenableNum.should.become("happy"),
+    thenableNum.should.eventually.have.property("fun times"),
+    thenableNum.should.be.rejectedWith(TypeError, "only joyful types are allowed")
+]).should.notify(() => console.log('done'));
+
+// Assert API
+var thenableVoid: PromisesAPlus.Thenable<void>;
+thenableVoid = chai.assert.eventually.equal(thenableNum, 4, 'Message');
+thenableVoid = chai.assert.isFulfilled(thenableNum, "optional message");
+thenableVoid = chai.assert.becomes(thenableNum, "foo", "optional message");
+thenableVoid = chai.assert.doesNotBecome(thenableNum, "foo", "optional message");
+thenableVoid = chai.assert.isRejected(thenableNum, "optional message");
+thenableVoid = chai.assert.isRejected(thenableNum, Error, "optional message");
+thenableVoid = chai.assert.isRejected(thenableNum, /error message matcher/, "optional message");
+
+// Check that original chai assertions are not broken
+var undef: void;
+undef = chai.assert.equal(10, 4, 'Message');
diff --git a/chai-as-promised/chai-as-promised.d.ts b/chai-as-promised/chai-as-promised.d.ts
index 106bbf41e8..51255b4902 100644
--- a/chai-as-promised/chai-as-promised.d.ts
+++ b/chai-as-promised/chai-as-promised.d.ts
@@ -1,9 +1,10 @@
 // Type definitions for chai-as-promised
 // Project: https://github.com/domenic/chai-as-promised/
-// Definitions by: jt000 <https://github.com/jt000>
+// Definitions by: jt000 <https://github.com/jt000>, Yuki Kokubun <https://github.com/Kuniwak>
 // Definitions: https://github.com/borisyankov/DefinitelyTyped
 
 /// <reference path="../chai/chai.d.ts" />
+/// <reference path="../promises-a-plus/promises-a-plus.d.ts" />
 
 declare module 'chai-as-promised' {
     function chaiAsPromised(chai: any, utils: any): void;
@@ -12,25 +13,272 @@ declare module 'chai-as-promised' {
 
 declare module Chai {
 
-    interface Assertion {
-        become(expected: any): Assertion;
-        fulfilled: Assertion;
-        rejected: Assertion;
-        rejectedWith(expected: any): Assertion;
-        notify(fn: Function): Assertion;
+    // For BDD API
+    interface Assertion extends LanguageChains, NumericComparison, TypeComparison {
+        eventually: PromisedAssertion;
+        become(expected: any): PromisedAssertion;
+        fulfilled: PromisedAssertion;
+        rejected: PromisedAssertion;
+        rejectedWith(expected: any, message?: string): PromisedAssertion;
+        notify(fn: Function): PromisedAssertion;
     }
 
-    interface LanguageChains {
-        eventually: Assertion;
+    // Eventually does not have .then(), but PromisedAssertion have.
+    interface Eventually extends PromisedLanguageChains, PromisedNumericComparison, PromisedTypeComparison {
+        // From chai-as-promised
+        become(expected: PromisesAPlus.Thenable<any>): PromisedAssertion;
+        fulfilled: PromisedAssertion;
+        rejected: PromisedAssertion;
+        rejectedWith(expected: any): PromisedAssertion;
+        notify(fn: Function): PromisedAssertion;
+
+        // From chai
+        not: PromisedAssertion;
+        deep: PromisedDeep;
+        a: PromisedTypeComparison;
+        an: PromisedTypeComparison;
+        include: PromisedInclude;
+        contain: PromisedInclude;
+        ok: PromisedAssertion;
+        true: PromisedAssertion;
+        false: PromisedAssertion;
+        null: PromisedAssertion;
+        undefined: PromisedAssertion;
+        exist: PromisedAssertion;
+        empty: PromisedAssertion;
+        arguments: PromisedAssertion;
+        Arguments: PromisedAssertion;
+        equal: PromisedEqual;
+        equals: PromisedEqual;
+        eq: PromisedEqual;
+        eql: PromisedEqual;
+        eqls: PromisedEqual;
+        property: PromisedProperty;
+        ownProperty: PromisedOwnProperty;
+        haveOwnProperty: PromisedOwnProperty;
+        length: PromisedLength;
+        lengthOf: PromisedLength;
+        match(regexp: RegExp|string, message?: string): PromisedAssertion;
+        string(string: string, message?: string): PromisedAssertion;
+        keys: PromisedKeys;
+        key(string: string): PromisedAssertion;
+        throw: PromisedThrow;
+        throws: PromisedThrow;
+        Throw: PromisedThrow;
+        respondTo(method: string, message?: string): PromisedAssertion;
+        itself: PromisedAssertion;
+        satisfy(matcher: Function, message?: string): PromisedAssertion;
+        closeTo(expected: number, delta: number, message?: string): PromisedAssertion;
+        members: PromisedMembers;
     }
 
+    interface PromisedAssertion extends Eventually, PromisesAPlus.Thenable<any> {
+    }
+
+    interface PromisedLanguageChains {
+        eventually: Eventually;
+
+        // From chai
+        to: PromisedAssertion;
+        be: PromisedAssertion;
+        been: PromisedAssertion;
+        is: PromisedAssertion;
+        that: PromisedAssertion;
+        which: PromisedAssertion;
+        and: PromisedAssertion;
+        has: PromisedAssertion;
+        have: PromisedAssertion;
+        with: PromisedAssertion;
+        at: PromisedAssertion;
+        of: PromisedAssertion;
+        same: PromisedAssertion;
+    }
+
+    interface PromisedNumericComparison {
+        above: PromisedNumberComparer;
+        gt: PromisedNumberComparer;
+        greaterThan: PromisedNumberComparer;
+        least: PromisedNumberComparer;
+        gte: PromisedNumberComparer;
+        below: PromisedNumberComparer;
+        lt: PromisedNumberComparer;
+        lessThan: PromisedNumberComparer;
+        most: PromisedNumberComparer;
+        lte: PromisedNumberComparer;
+        within(start: number, finish: number, message?: string): PromisedAssertion;
+    }
+
+    interface PromisedNumberComparer {
+        (value: number, message?: string): PromisedAssertion;
+    }
+
+    interface PromisedTypeComparison {
+        (type: string, message?: string): PromisedAssertion;
+        instanceof: PromisedInstanceOf;
+        instanceOf: PromisedInstanceOf;
+    }
+
+    interface PromisedInstanceOf {
+        (constructor: Object, message?: string): PromisedAssertion;
+    }
+
+    interface PromisedDeep {
+        equal: PromisedEqual;
+        include: PromisedInclude;
+        property: PromisedProperty;
+    }
+
+    interface PromisedEqual {
+        (value: any, message?: string): PromisedAssertion;
+    }
+
+    interface PromisedProperty {
+        (name: string, value?: any, message?: string): PromisedAssertion;
+    }
+
+    interface PromisedOwnProperty {
+        (name: string, message?: string): PromisedAssertion;
+    }
+
+    interface PromisedLength extends PromisedLanguageChains, PromisedNumericComparison {
+        (length: number, message?: string): PromisedAssertion;
+    }
+
+    interface PromisedInclude {
+        (value: Object, message?: string): PromisedAssertion;
+        (value: string, message?: string): PromisedAssertion;
+        (value: number, message?: string): PromisedAssertion;
+        keys: PromisedKeys;
+        members: PromisedMembers;
+    }
+
+    interface PromisedKeys {
+        (...keys: string[]): PromisedAssertion;
+        (keys: any[]): PromisedAssertion;
+    }
+
+    interface PromisedThrow {
+        (): PromisedAssertion;
+        (expected: string, message?: string): PromisedAssertion;
+        (expected: RegExp, message?: string): PromisedAssertion;
+        (constructor: Error, expected?: string, message?: string): PromisedAssertion;
+        (constructor: Error, expected?: RegExp, message?: string): PromisedAssertion;
+        (constructor: Function, expected?: string, message?: string): PromisedAssertion;
+        (constructor: Function, expected?: RegExp, message?: string): PromisedAssertion;
+    }
+
+    interface PromisedMembers {
+        (set: any[], message?: string): PromisedAssertion;
+    }
+
+    // For Assert API
     interface Assert {
-        eventually: Assert;
-        isFulfilled(promise: any, message?: string): void;
-        becomes(promise: any, expected: any, message?: string): void;
-        doesNotBecome(promise: any, expected: any, message?: string): void;
-        isRejected(promise: any, message?: string): void;
-        isRejected(promise: any, expected: any, message?: string): void;
-        isRejected(promise: any, match: RegExp, message?: string): void;
+        eventually: PromisedAssert;
+        isFulfilled(promise: PromisesAPlus.Thenable<any>, message?: string): PromisesAPlus.Thenable<void>;
+        becomes(promise: PromisesAPlus.Thenable<any>, expected: any, message?: string): PromisesAPlus.Thenable<void>;
+        doesNotBecome(promise: PromisesAPlus.Thenable<any>, expected: any, message?: string): PromisesAPlus.Thenable<void>;
+        isRejected(promise: PromisesAPlus.Thenable<any>, message?: string): PromisesAPlus.Thenable<void>;
+        isRejected(promise: PromisesAPlus.Thenable<any>, expected: any, message?: string): PromisesAPlus.Thenable<void>;
+        isRejected(promise: PromisesAPlus.Thenable<any>, match: RegExp, message?: string): PromisesAPlus.Thenable<void>;
+        notify(fn: Function): PromisesAPlus.Thenable<void>;
+    }
+
+    export interface PromisedAssert {
+        fail(actual?: any, expected?: any, msg?: string, operator?: string): PromisesAPlus.Thenable<void>;
+
+        ok(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+        notOk(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        equal(act: any, exp: any, msg?: string): PromisesAPlus.Thenable<void>;
+        notEqual(act: any, exp: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        strictEqual(act: any, exp: any, msg?: string): PromisesAPlus.Thenable<void>;
+        notStrictEqual(act: any, exp: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        deepEqual(act: any, exp: any, msg?: string): PromisesAPlus.Thenable<void>;
+        notDeepEqual(act: any, exp: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        isTrue(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+        isFalse(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        isNull(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+        isNotNull(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        isUndefined(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+        isDefined(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        isFunction(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+        isNotFunction(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        isObject(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+        isNotObject(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        isArray(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+        isNotArray(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        isString(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+        isNotString(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        isNumber(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+        isNotNumber(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        isBoolean(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+        isNotBoolean(val: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        typeOf(val: any, type: string, msg?: string): PromisesAPlus.Thenable<void>;
+        notTypeOf(val: any, type: string, msg?: string): PromisesAPlus.Thenable<void>;
+
+        instanceOf(val: any, type: Function, msg?: string): PromisesAPlus.Thenable<void>;
+        notInstanceOf(val: any, type: Function, msg?: string): PromisesAPlus.Thenable<void>;
+
+        include(exp: string, inc: any, msg?: string): PromisesAPlus.Thenable<void>;
+        include(exp: any[], inc: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        notInclude(exp: string, inc: any, msg?: string): PromisesAPlus.Thenable<void>;
+        notInclude(exp: any[], inc: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        match(exp: any, re: RegExp, msg?: string): PromisesAPlus.Thenable<void>;
+        notMatch(exp: any, re: RegExp, msg?: string): PromisesAPlus.Thenable<void>;
+
+        property(obj: Object, prop: string, msg?: string): PromisesAPlus.Thenable<void>;
+        notProperty(obj: Object, prop: string, msg?: string): PromisesAPlus.Thenable<void>;
+        deepProperty(obj: Object, prop: string, msg?: string): PromisesAPlus.Thenable<void>;
+        notDeepProperty(obj: Object, prop: string, msg?: string): PromisesAPlus.Thenable<void>;
+
+        propertyVal(obj: Object, prop: string, val: any, msg?: string): PromisesAPlus.Thenable<void>;
+        propertyNotVal(obj: Object, prop: string, val: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        deepPropertyVal(obj: Object, prop: string, val: any, msg?: string): PromisesAPlus.Thenable<void>;
+        deepPropertyNotVal(obj: Object, prop: string, val: any, msg?: string): PromisesAPlus.Thenable<void>;
+
+        lengthOf(exp: any, len: number, msg?: string): PromisesAPlus.Thenable<void>;
+        //alias frenzy
+        throw(fn: Function, msg?: string): PromisesAPlus.Thenable<void>;
+        throw(fn: Function, regExp: RegExp): PromisesAPlus.Thenable<void>;
+        throw(fn: Function, errType: Function, msg?: string): PromisesAPlus.Thenable<void>;
+        throw(fn: Function, errType: Function, regExp: RegExp): PromisesAPlus.Thenable<void>;
+
+        throws(fn: Function, msg?: string): PromisesAPlus.Thenable<void>;
+        throws(fn: Function, regExp: RegExp): PromisesAPlus.Thenable<void>;
+        throws(fn: Function, errType: Function, msg?: string): PromisesAPlus.Thenable<void>;
+        throws(fn: Function, errType: Function, regExp: RegExp): PromisesAPlus.Thenable<void>;
+
+        Throw(fn: Function, msg?: string): PromisesAPlus.Thenable<void>;
+        Throw(fn: Function, regExp: RegExp): PromisesAPlus.Thenable<void>;
+        Throw(fn: Function, errType: Function, msg?: string): PromisesAPlus.Thenable<void>;
+        Throw(fn: Function, errType: Function, regExp: RegExp): PromisesAPlus.Thenable<void>;
+
+        doesNotThrow(fn: Function, msg?: string): PromisesAPlus.Thenable<void>;
+        doesNotThrow(fn: Function, regExp: RegExp): PromisesAPlus.Thenable<void>;
+        doesNotThrow(fn: Function, errType: Function, msg?: string): PromisesAPlus.Thenable<void>;
+        doesNotThrow(fn: Function, errType: Function, regExp: RegExp): PromisesAPlus.Thenable<void>;
+
+        operator(val: any, operator: string, val2: any, msg?: string): PromisesAPlus.Thenable<void>;
+        closeTo(act: number, exp: number, delta: number, msg?: string): PromisesAPlus.Thenable<void>;
+
+        sameMembers(set1: any[], set2: any[], msg?: string): PromisesAPlus.Thenable<void>;
+        includeMembers(set1: any[], set2: any[], msg?: string): PromisesAPlus.Thenable<void>;
+
+        ifError(val: any, msg?: string): PromisesAPlus.Thenable<void>;
     }
 }