diff --git a/test/cli/cli.test.js b/test/cli/cli.test.js
index e4106217b2..60618eb544 100644
--- a/test/cli/cli.test.js
+++ b/test/cli/cli.test.js
@@ -25,9 +25,7 @@ describe('CLI', () => {
     const { code, stderr } = await testBin('--progress --profile');
     expect(code).toEqual(0);
     // should profile
-    expect(output.stderr.includes('after chunk modules optimization')).toBe(
-      true
-    );
+    expect(stderr.includes('after chunk modules optimization')).toBe(true);
   });
 
   it('--bonjour', async () => {
@@ -58,8 +56,8 @@ describe('CLI', () => {
   });
 
   it('unspecified port', async () => {
-    const { output } = await testBin('');
-    expect(/http:\/\/localhost:[0-9]+/.test(output.stdout)).toEqual(true);
+    const { stdout } = await testBin('');
+    expect(/http:\/\/localhost:[0-9]+/.test(stdout)).toEqual(true);
   });
 
   it('--color', async () => {
diff --git a/test/client/socket-helper.test.js b/test/client/socket-helper.test.js
index a40007aa49..b8074cebd5 100644
--- a/test/client/socket-helper.test.js
+++ b/test/client/socket-helper.test.js
@@ -8,7 +8,7 @@ describe('socket', () => {
 
   it('should default to SockJSClient when no __webpack_dev_server_client__ set', () => {
     jest.mock('../../client/clients/SockJSClient');
-    const socket = require('../../client/socket');
+    const { default: socket } = require('../../client/socket');
     const SockJSClient = require('../../client/clients/SockJSClient');
 
     const mockHandler = jest.fn();
@@ -36,7 +36,7 @@ describe('socket', () => {
 
   it('should use __webpack_dev_server_client__ when set', () => {
     jest.mock('../../client/clients/SockJSClient');
-    const socket = require('../../client/socket');
+    const { default: socket } = require('../../client/socket');
     global.__webpack_dev_server_client__ = require('../../client/clients/SockJSClient');
 
     const mockHandler = jest.fn();
diff --git a/test/e2e/ClientOptions.test.js b/test/e2e/ClientOptions.test.js
index b753f1a24e..6f2c5ac8d9 100644
--- a/test/e2e/ClientOptions.test.js
+++ b/test/e2e/ClientOptions.test.js
@@ -50,19 +50,17 @@ describe('Client code', () => {
     });
 
     afterAll((done) => {
-      proxy.close(() => {
-        done();
-      });
+      proxy.close(done);
     });
 
-    it('responds with a 200', (done) => {
+    it('responds with a 200', async () => {
       {
         const req = request(`http://localhost:${port2}`);
-        req.get('/sockjs-node').expect(200, 'Welcome to SockJS!\n', done);
+        await req.get('/sockjs-node').expect(200, 'Welcome to SockJS!\n');
       }
       {
         const req = request(`http://localhost:${port1}`);
-        req.get('/sockjs-node').expect(200, 'Welcome to SockJS!\n', done);
+        await req.get('/sockjs-node').expect(200, 'Welcome to SockJS!\n');
       }
     });
 
@@ -297,47 +295,34 @@ describe('Client console.log', () => {
     },
   ];
 
-  cases.forEach(({ title, options }) => {
-    it(title, (done) => {
+  for (const { title, options } of cases) {
+    it(title, async () => {
       const res = [];
       const testOptions = Object.assign({}, baseOptions, options);
 
-      // TODO: use async/await when Node.js v6 support is dropped
-      Promise.resolve()
-        .then(() => {
-          return new Promise((resolve) => {
-            testServer.startAwaitingCompilation(config, testOptions, resolve);
-          });
-        })
-        .then(() => {
-          // make sure the previous Promise is not passing along strange arguments to runBrowser
-          return runBrowser();
-        })
-        .then(({ page, browser }) => {
-          return new Promise((resolve) => {
-            page.goto(`http://localhost:${port2}/main`);
-            page.on('console', ({ _text }) => {
-              res.push(_text);
-            });
-            // wait for load before closing the browser
-            page.waitForNavigation({ waitUntil: 'load' }).then(() => {
-              page.waitFor(beforeBrowserCloseDelay).then(() => {
-                browser.close().then(() => {
-                  resolve();
-                });
-              });
-            });
-          });
-        })
-        .then(() => {
-          return new Promise((resolve) => {
-            testServer.close(resolve);
-          });
-        })
-        .then(() => {
-          expect(res).toMatchSnapshot();
-          done();
-        });
+      // TODO: refactor(hiroppy)
+      await new Promise((resolve) => {
+        testServer.startAwaitingCompilation(config, testOptions, resolve);
+      });
+
+      const { page, browser } = await runBrowser();
+
+      page.goto(`http://localhost:${port2}/main`);
+      page.on('console', ({ _text }) => {
+        res.push(_text);
+      });
+
+      // wait for load before closing the browser
+      await page.waitForNavigation({ waitUntil: 'load' });
+      await page.waitFor(beforeBrowserCloseDelay);
+      await browser.close();
+
+      expect(res).toMatchSnapshot();
+
+      // TODO: refactor(hiroppy)
+      await new Promise((resolve) => {
+        testServer.close(resolve);
+      });
     });
-  });
+  }
 });
diff --git a/test/server/servers/SockJSServer.test.js b/test/server/servers/SockJSServer.test.js
index 054ec18f31..c3203f3627 100644
--- a/test/server/servers/SockJSServer.test.js
+++ b/test/server/servers/SockJSServer.test.js
@@ -37,7 +37,8 @@ describe('SockJSServer', () => {
       const data = [];
       let headers;
 
-      socketServer.onConnection(async (connection) => {
+      socketServer.onConnection(async (connection, h) => {
+        headers = h;
         data.push('open');
         socketServer.send(connection, 'hello world');
 
diff --git a/test/server/utils/runOpen.test.js b/test/server/utils/runOpen.test.js
index 0c37e488b0..1ae6b092d1 100644
--- a/test/server/utils/runOpen.test.js
+++ b/test/server/utils/runOpen.test.js
@@ -78,13 +78,14 @@ describe('runOpen util', () => {
     });
   });
 
-  it('on specify absolute https URL with page in Google Chrome ', () => {
-    return runOpen(
+  it('on specify absolute https URL with page in Google Chrome ', async () => {
+    await runOpen(
       'https://example.com',
       { open: 'Google Chrome', openPage: 'https://example2.com' },
       console
-    ).then(() => {
-      expect(open.mock.calls[0]).toMatchInlineSnapshot(`
+    );
+
+    expect(open.mock.calls[0]).toMatchInlineSnapshot(`
           Array [
             "https://example2.com",
             Object {
@@ -93,16 +94,16 @@ describe('runOpen util', () => {
             },
           ]
         `);
-    });
   });
 
-  it('on specify absolute http URL with page in Google Chrome ', () => {
-    return runOpen(
+  it('on specify absolute http URL with page in Google Chrome ', async () => {
+    runOpen(
       'https://example.com',
       { open: 'Google Chrome', openPage: 'http://example2.com' },
       console
-    ).then(() => {
-      expect(open.mock.calls[0]).toMatchInlineSnapshot(`
+    );
+
+    expect(open.mock.calls[0]).toMatchInlineSnapshot(`
           Array [
             "http://example2.com",
             Object {
@@ -111,7 +112,6 @@ describe('runOpen util', () => {
             },
           ]
         `);
-    });
   });
 
   describe('should not open browser', () => {