diff --git a/e2e/contents/navigate.test.js b/e2e/contents/navigate.test.js
index b3f5f32..d36b167 100644
--- a/e2e/contents/navigate.test.js
+++ b/e2e/contents/navigate.test.js
@@ -7,150 +7,96 @@ import { CLIENT_URL } from '../web-server/url';
 describe("navigate test", () => {
   let targetWindow;
 
-  before(() => {
-    return windows.create().then((win) => {
-      targetWindow = win;
-      return tabs.create(targetWindow.id, CLIENT_URL);
-    });
+  before(async () => {
+    targetWindow = await windows.create();
+    await tabs.create(targetWindow.id, CLIENT_URL);
   });
 
-  after(() => {
-    return windows.remove(targetWindow.id);
+  after(async () => {
+    await windows.remove(targetWindow.id);
   });
 
-  it('goes to parent', () => {
-    let targetTab;
-    return tabs.create(targetWindow.id, CLIENT_URL + '/a/b/c').then((tab) => {
-      targetTab = tab;
-      return keys.press(targetTab.id, 'g');
-    }).then(() => {
-      return keys.press(targetTab.id, 'u');
-    }).then(() => {
-      return new Promise(resolve => { setTimeout(() => resolve(), 10) });
-    }).then(() => {
-      return tabs.get(targetTab.id);
-    }).then((tab) => {
-      expect(tab.url).to.be.equal(CLIENT_URL + '/a/b/');
-    });
+  it('goes to parent', async () => {
+    let tab = await tabs.create(targetWindow.id, CLIENT_URL + '/a/b/c');
+    await keys.press(tab.id, 'g');
+    await keys.press(tab.id, 'u');
+    await new Promise(resolve => { setTimeout(() => resolve(), 10) });
+
+    tab = await tabs.get(tab.id);
+    expect(tab.url).to.be.equal(CLIENT_URL + '/a/b/');
   });
 
-  it('removes hash', () => {
-    let targetTab;
-    return tabs.create(targetWindow.id, CLIENT_URL + '/a/b/c#navigate').then((tab) => {
-      targetTab = tab;
-      return keys.press(targetTab.id, 'g');
-    }).then(() => {
-      return keys.press(targetTab.id, 'u');
-    }).then(() => {
-      return tabs.get(targetTab.id);
-    }).then((tab) => {
-      expect(tab.url).to.be.equal(CLIENT_URL + '/a/b/c#');
-    });
+  it('removes hash', async () => {
+    let tab = await tabs.create(targetWindow.id, CLIENT_URL + '/a/b/c#navigate');
+    await keys.press(tab.id, 'g');
+    await keys.press(tab.id, 'u');
+    tab = await tabs.get(tab.id);
+    expect(tab.url).to.be.equal(CLIENT_URL + '/a/b/c#');
   });
 
-  it('goes to root', () => {
-    let targetTab;
-    return tabs.create(targetWindow.id, CLIENT_URL + '/a/b/c').then((tab) => {
-      targetTab = tab;
-      return keys.press(targetTab.id, 'g');
-    }).then(() => {
-      return keys.press(targetTab.id, 'U', { shiftKey: true });
-    }).then(() => {
-      return new Promise(resolve => { setTimeout(() => resolve(), 10) });
-    }).then(() => {
-      return tabs.get(targetTab.id);
-    }).then((tab) => {
-      expect(tab.url).to.be.equal(CLIENT_URL + '/');
-    });
+  it('goes to root', async () => {
+    let tab = await tabs.create(targetWindow.id, CLIENT_URL + '/a/b/c');
+    await keys.press(tab.id, 'g');
+    await keys.press(tab.id, 'U', { shiftKey: true });
+    await new Promise(resolve => { setTimeout(() => resolve(), 10) });
+
+    tab = await tabs.get(tab.id);
+    expect(tab.url).to.be.equal(CLIENT_URL + '/');
   });
 
-  it('goes back and forward in history', () => {
-    let targetTab;
-    return tabs.create(targetWindow.id, CLIENT_URL + '/#navigate').then((tab) => {
-      targetTab = tab;
-      return keys.press(targetTab.id, 'g');
-    }).then(() => {
-      return keys.press(targetTab.id, 'u');
-    }).then(() => {
-      return keys.press(targetTab.id, 'H', { shiftKey: true });
-    }).then(() => {
-      return new Promise(resolve => { setTimeout(() => resolve(), 10) });
-    }).then(() => {
-      return tabs.get(targetTab.id);
-    }).then((tab) => {
-      expect(tab.url, 'go back in history').to.be.equal(CLIENT_URL + '/#navigate');
-    }).then(() => {
-      return new Promise(resolve => { setTimeout(() => resolve(), 10) });
-    }).then(() => {
-      return keys.press(targetTab.id, 'L', { shiftKey: true });
-    }).then(() => {
-      return tabs.get(targetTab.id);
-    }).then((tab) => {
-      expect(tab.url, 'go next in history').to.be.equal(CLIENT_URL + '/#');
-    });
+  it('goes back and forward in history', async () => {
+    let tab = await tabs.create(targetWindow.id, CLIENT_URL + '/#navigate');
+    await keys.press(tab.id, 'g');
+    await keys.press(tab.id, 'u');
+    await keys.press(tab.id, 'H', { shiftKey: true });
+    await new Promise(resolve => { setTimeout(() => resolve(), 10) });
+
+    tab = await tabs.get(tab.id);
+    expect(tab.url, 'go back in history').to.be.equal(CLIENT_URL + '/#navigate');
+    await new Promise(resolve => { setTimeout(() => resolve(), 10) });
+    await keys.press(tab.id, 'L', { shiftKey: true });
+
+    tab = await tabs.get(tab.id);
+    expect(tab.url, 'go next in history').to.be.equal(CLIENT_URL + '/#');
   });
 
-  it('goes previous page by <a>', () => {
-    let targetTab;
-    return tabs.create(targetWindow.id, CLIENT_URL + '/a-pagenation?page=10').then((tab) => {
-      targetTab = tab;
-      return keys.press(targetTab.id, '[');
-    }).then(() => {
-      return keys.press(targetTab.id, '[');
-    }).then(() => {
-      return new Promise(resolve => { setTimeout(() => resolve(), 10) });
-    }).then(() => {
-      return tabs.get(targetTab.id);
-    }).then((tab) => {
-      expect(tab.url).to.be.equal(CLIENT_URL + '/a-pagenation?page=9');
-    });
+  it('goes previous page by <a>', async () => {
+    let tab = await tabs.create(targetWindow.id, CLIENT_URL + '/a-pagenation?page=10');
+    await keys.press(tab.id, '[');
+    await keys.press(tab.id, '[');
+    await new Promise(resolve => { setTimeout(() => resolve(), 10) });
+
+    tab = await tabs.get(tab.id);
+    expect(tab.url).to.be.equal(CLIENT_URL + '/a-pagenation?page=9');
   })
 
-  it('goes next page by <a>', () => {
-    let targetTab;
-    return tabs.create(targetWindow.id, CLIENT_URL + '/a-pagenation?page=10').then((tab) => {
-      targetTab = tab;
-      return keys.press(targetTab.id, ']');
-    }).then(() => {
-      return keys.press(targetTab.id, ']');
-    }).then(() => {
-      return new Promise(resolve => { setTimeout(() => resolve(), 10) });
-    }).then(() => {
-      return tabs.get(targetTab.id);
-    }).then((tab) => {
-      expect(tab.url).to.be.equal(CLIENT_URL + '/a-pagenation?page=11');
-    });
+  it('goes next page by <a>', async () => {
+    let tab = await tabs.create(targetWindow.id, CLIENT_URL + '/a-pagenation?page=10');
+    await keys.press(tab.id, ']');
+    await keys.press(tab.id, ']');
+    await new Promise(resolve => { setTimeout(() => resolve(), 10) });
+
+    tab = await tabs.get(tab.id);
+    expect(tab.url).to.be.equal(CLIENT_URL + '/a-pagenation?page=11');
   })
 
-  it('goes previous page by <link>', () => {
-    let targetTab;
-    return tabs.create(targetWindow.id, CLIENT_URL + '/link-pagenation?page=10').then((tab) => {
-      targetTab = tab;
-      return keys.press(targetTab.id, '[');
-    }).then(() => {
-      return keys.press(targetTab.id, '[');
-    }).then(() => {
-      return new Promise(resolve => { setTimeout(() => resolve(), 10) });
-    }).then(() => {
-      return tabs.get(targetTab.id);
-    }).then((tab) => {
-      expect(tab.url).to.be.equal(CLIENT_URL + '/link-pagenation?page=9');
-    });
+  it('goes previous page by <link>', async () => {
+    let tab = await tabs.create(targetWindow.id, CLIENT_URL + '/link-pagenation?page=10');
+    await keys.press(tab.id, '[');
+    await keys.press(tab.id, '[');
+    await new Promise(resolve => { setTimeout(() => resolve(), 10) });
+
+    tab = await tabs.get(tab.id);
+    expect(tab.url).to.be.equal(CLIENT_URL + '/link-pagenation?page=9');
   })
 
-  it('goes next page by <link>', () => {
-    let targetTab;
-    return tabs.create(targetWindow.id, CLIENT_URL + '/link-pagenation?page=10').then((tab) => {
-      targetTab = tab;
-      return keys.press(targetTab.id, ']');
-    }).then(() => {
-      return keys.press(targetTab.id, ']');
-    }).then(() => {
-      return new Promise(resolve => { setTimeout(() => resolve(), 10) });
-    }).then(() => {
-      return tabs.get(targetTab.id);
-    }).then((tab) => {
-      expect(tab.url).to.be.equal(CLIENT_URL + '/link-pagenation?page=11');
-    });
+  it('goes next page by <link>', async () => {
+    let tab = await tabs.create(targetWindow.id, CLIENT_URL + '/link-pagenation?page=10');
+    await keys.press(tab.id, ']');
+    await keys.press(tab.id, ']');
+    await new Promise(resolve => { setTimeout(() => resolve(), 10) });
+
+    tab = await tabs.get(tab.id);
+    expect(tab.url).to.be.equal(CLIENT_URL + '/link-pagenation?page=11');
   })
 });
diff --git a/e2e/contents/tab.test.js b/e2e/contents/tab.test.js
index 3b2e7b5..2d7f548 100644
--- a/e2e/contents/tab.test.js
+++ b/e2e/contents/tab.test.js
@@ -92,7 +92,7 @@ describe("tab test", () => {
     await tabs.create(targetWindow.id, CLIENT_URL + '#2');
     await tabs.create(targetWindow.id, CLIENT_URL + '#3');
     let tab = await tabs.selectAt(targetWindow.id, 2);
-    await keys.press(tab.id, 'g').then(() => tab);
+    await keys.press(tab.id, 'g');
     await keys.press(tab.id, '0');
 
     let win = await windows.get(targetWindow.id);