diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 0000000..710a33c
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,31 @@
+name: build
+
+on: [push, pull_request]
+
+concurrency:
+  group: ${{github.workflow}}-${{github.event_name}}-${{github.ref}}
+  cancel-in-progress: true
+
+jobs:
+  test-and-build:
+    runs-on: macos-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Install Node.js
+        uses: actions/setup-node@v3
+        with:
+          node-version: 13
+
+      - name: Install Dependencies
+        run: npm install
+
+      - name: Run build & test
+        run: |
+          npm run build
+
+      - name: Coveralls GitHub Action
+        uses: coverallsapp/github-action@v2.2.3
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.npmignore b/.npmignore
index 7937633..e825736 100644
--- a/.npmignore
+++ b/.npmignore
@@ -6,4 +6,3 @@ package-lock.json
 __tests__
 src
 .babelrc
-.travis.yml
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 8a37dfe..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,10 +0,0 @@
-language: node_js
-node_js:
-    - "8"
-    - "9"
-    - "10"
-    - "11"
-    - "12"
-    - "13"
-after_success:
-    - npm run coveralls
diff --git a/README.md b/README.md
index f17fd0e..e0b137b 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 > Mock `Date` when run unit test cases with jest. Make tests of `Date` easier.
 
-[![Build Status](https://travis-ci.org/hustcc/jest-date-mock.svg?branch=master)](https://travis-ci.org/hustcc/jest-date-mock)
+[![Build Status](https://github.com/hustcc/jest-date-mock/workflows/build/badge.svg)](https://github.com/hustcc/jest-date-mock/actions)
 [![Coverage Status](https://coveralls.io/repos/github/hustcc/jest-date-mock/badge.svg?branch=master)](https://coveralls.io/github/hustcc/jest-date-mock)
 [![npm](https://img.shields.io/npm/v/jest-date-mock.svg)](https://www.npmjs.com/package/jest-date-mock)
 [![npm](https://img.shields.io/npm/dm/jest-date-mock.svg)](https://www.npmjs.com/package/jest-date-mock)
diff --git a/__tests__/index.js b/__tests__/index.js
index c223548..f6c2174 100644
--- a/__tests__/index.js
+++ b/__tests__/index.js
@@ -15,16 +15,24 @@ describe('jest-date-mock', () => {
     // Date isEqual
     expect(new Date()).toEqual(new Date(0));
 
+    // .constructor()
+    expect(+new Date(1000).constructor()).toBe(0);
+    expect(+new Date().constructor(10000)).toBe(10000);
+    expect(new Date().constructor(10000)).toBeInstanceOf(Date);
+
+
     // +
     expect(+new Date()).toBe(0);
     expect(+new Date(10000)).toBe(10000);
 
+
     // getTime
     expect(new Date().getTime()).toBe(0);
     expect(new Date(10000).getTime()).toBe(10000);
 
     // instanceof
     expect(new Date()).toBeInstanceOf(Date);
+    expect(new Date().constructor(10000)).toBeInstanceOf(Date);
 
     // 2018-05-27 08:00:00
     expect(new Date(Date.UTC(2018, 5, 27, 0, 0, 0)).getTime()).toBe(1530057600000);
@@ -91,6 +99,9 @@ describe('jest-date-mock', () => {
     expect(+new Date() - now).toBe(0);
     advanceBy();
     expect(+new Date() - now).toBe(0);
+
+    advanceBy(3000);
+    expect(+new Date().constructor() - now).toBe(3000); // .constructor()
   });
 
   test('clear', () => {
@@ -99,6 +110,7 @@ describe('jest-date-mock', () => {
 
     advanceTo();
     expect(+new Date()).toBe(0);
+    expect(+new Date().constructor()).toBe(0);
   });
 
   test('usage', () => {
diff --git a/package.json b/package.json
index 36438ee..5b36abc 100644
--- a/package.json
+++ b/package.json
@@ -6,8 +6,7 @@
   "typings": "lib/index.d.ts",
   "scripts": {
     "test": "jest --no-cache",
-    "build": "babel src --out-dir lib --copy-files && npm run test",
-    "coveralls": "cat ./coverage/lcov.info | coveralls"
+    "build": "babel src --out-dir lib --copy-files && npm run test"
   },
   "repository": {
     "type": "git",
@@ -33,7 +32,6 @@
     "@babel/preset-env": "^7.7.7",
     "babel-jest": "^24.9.0",
     "babel-plugin-version": "^0.2.2",
-    "coveralls": "^3.0.0",
     "jest": "^24.9.0"
   },
   "jest": {
diff --git a/src/mockDate.js b/src/mockDate.js
index b3b54d1..7d7dc45 100644
--- a/src/mockDate.js
+++ b/src/mockDate.js
@@ -13,6 +13,7 @@ export const mockDateClass = D => {
     const dateArgs = args.length === 0 ? [mockNow()] : args;
     const instance = new D(...dateArgs);
     Object.setPrototypeOf(instance, Object.getPrototypeOf(this));
+    instance.constructor = Date;
     return instance;
   }