gistfile0.txt

diff --git a/package.json b/package.json
index f2277a1..b749b54 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,7 @@
   "description": "",
   "main": "index.js",
   "scripts": {
-    "cc": "rimraf ./node_modules/.cache && nyc mocha -r esm test/**/*.spec.js"
+    "cc": "rimraf ./node_modules/.cache && nyc mocha test/**/*.spec.js"
   },
   "keywords": [],
   "author": "",
diff --git a/src/index.js b/src/index.js
index 7d65831..4ae133c 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,3 +1,5 @@
-export function add(a, b) {
-  return a + b;
+module.exports = {
+  add: function (a, b) {
+    return a + b;
+  }
 }
diff --git a/test/basic.spec.js b/test/basic.spec.js
index c2ea7f6..b29785d 100644
--- a/test/basic.spec.js
+++ b/test/basic.spec.js
@@ -1,5 +1,5 @@
-import { add } from "../src/index";
-import { strict as assert } from 'assert';
+const { add } = require("../src/index");
+const { strict: assert } = require('assert');
 
 describe("basic test", () => {
   it("add correctly", () => {