diff --git a/chromium.js b/chromium.js
index 12432c0807..d0e27ffbf6 100644
--- a/chromium.js
+++ b/chromium.js
@@ -14,15 +14,4 @@
  * limitations under the License.
  */
 
-const {helper} = require('./lib/helper');
-const api = require('./lib/api');
-for (const className in api.Chromium) {
-  // Playwright-web excludes certain classes from bundle, e.g. BrowserFetcher.
-  if (typeof api.Chromium[className] === 'function')
-    helper.installAsyncStackHooks(api.Chromium[className]);
-}
-
-const { CRPlaywright } = require('./lib/chromium/crPlaywright');
-const packageJson = require('./package.json');
-
-module.exports = new CRPlaywright(__dirname, packageJson.playwright.chromium_revision);
+module.exports = require('./index').playwright('chromium');
diff --git a/firefox.js b/firefox.js
index 58b92dcf90..f45f7ee57b 100644
--- a/firefox.js
+++ b/firefox.js
@@ -14,15 +14,4 @@
  * limitations under the License.
  */
 
-const {helper} = require('./lib/helper');
-const api = require('./lib/api');
-for (const className in api.Firefox) {
-  // Playwright-web excludes certain classes from bundle, e.g. BrowserFetcher.
-  if (typeof api.Firefox[className] === 'function')
-    helper.installAsyncStackHooks(api.Firefox[className]);
-}
-
-const { FFPlaywright } = require('./lib/firefox/ffPlaywright');
-const packageJson = require('./package.json');
-
-module.exports = new FFPlaywright(__dirname, packageJson.playwright.firefox_revision);
+module.exports = require('./index').playwright('firefox');
diff --git a/index.js b/index.js
index e3d0c539d7..2b8b9603e4 100644
--- a/index.js
+++ b/index.js
@@ -1,12 +1,22 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT license.
 
+const {helper} = require('./lib/helper');
+const api = require('./lib/api');
+const packageJson = require('./package.json');
+
+for (const className in api) {
+  // Playwright-web excludes certain classes from bundle, e.g. BrowserFetcher.
+  if (typeof api[className] === 'function')
+    helper.installAsyncStackHooks(api[className]);
+}
+
 module.exports.playwright = browser => {
   if (browser === 'chromium')
-    return require('./chromium');
+    return new api.Chromium(__dirname, packageJson.playwright.chromium_revision);
   if (browser === 'firefox')
-    return require('./firefox');
+    return new api.Firefox(__dirname, packageJson.playwright.firefox_revision);
   if (browser === 'webkit')
-    return require('./webkit');
+    return new api.WebKit(__dirname, packageJson.playwright.webkit_revision);
   throw new Error(`Unsupported browser "${browser}"`);
 };
diff --git a/src/frames.ts b/src/frames.ts
index 40853ab7fb..6830ad5fdd 100644
--- a/src/frames.ts
+++ b/src/frames.ts
@@ -651,7 +651,7 @@ export class Frame {
     await handle.dispose();
   }
 
-  waitFor(selectorOrFunctionOrTimeout: (string | number | Function), options: any = {}, ...args: any[]): Promise<js.JSHandle | null> {
+  async waitFor(selectorOrFunctionOrTimeout: (string | number | Function), options: any = {}, ...args: any[]): Promise<js.JSHandle | null> {
     if (helper.isString(selectorOrFunctionOrTimeout))
       return this.waitForSelector(selectorOrFunctionOrTimeout as string, options) as any;
     if (helper.isNumber(selectorOrFunctionOrTimeout))
@@ -691,7 +691,7 @@ export class Frame {
     return result.asElement() as dom.ElementHandle<Element>;
   }
 
-  waitForFunction(pageFunction: Function | string, options?: types.WaitForFunctionOptions, ...args: any[]): Promise<js.JSHandle> {
+  async waitForFunction(pageFunction: Function | string, options?: types.WaitForFunctionOptions, ...args: any[]): Promise<js.JSHandle> {
     options = { timeout: this._page._timeoutSettings.timeout(), ...(options || {}) };
     const task = dom.waitForFunctionTask(undefined, pageFunction, options, ...args);
     return this._scheduleRerunnableTask(task, 'main', options.timeout);
diff --git a/src/page.ts b/src/page.ts
index 24160c1159..4ee26a24c9 100644
--- a/src/page.ts
+++ b/src/page.ts
@@ -177,11 +177,11 @@ export class Page extends EventEmitter {
     return this.mainFrame().evaluateHandle(pageFunction, ...args as any);
   }
 
-  $eval: types.$Eval = (selector, pageFunction, ...args) => {
+  $eval: types.$Eval = async  (selector, pageFunction, ...args) => {
     return this.mainFrame().$eval(selector, pageFunction, ...args as any);
   }
 
-  $$eval: types.$$Eval = (selector, pageFunction, ...args) => {
+  $$eval: types.$$Eval = async (selector, pageFunction, ...args) => {
     return this.mainFrame().$$eval(selector, pageFunction, ...args as any);
   }
 
@@ -279,15 +279,15 @@ export class Page extends EventEmitter {
     return this.mainFrame().url();
   }
 
-  content(): Promise<string> {
+  async content(): Promise<string> {
     return this.mainFrame().content();
   }
 
-  setContent(html: string, options?: frames.NavigateOptions): Promise<void> {
+  async setContent(html: string, options?: frames.NavigateOptions): Promise<void> {
     return this.mainFrame().setContent(html, options);
   }
 
-  goto(url: string, options?: frames.GotoOptions): Promise<network.Response | null> {
+  async goto(url: string, options?: frames.GotoOptions): Promise<network.Response | null> {
     return this.mainFrame().goto(url, options);
   }
 
@@ -346,7 +346,6 @@ export class Page extends EventEmitter {
     return waitPromise;
   }
 
-
   async emulateMedia(options: { type?: input.MediaType, colorScheme?: input.ColorScheme }) {
     assert(!options.type || input.mediaTypes.has(options.type), 'Unsupported media type: ' + options.type);
     assert(!options.colorScheme || input.mediaColorSchemes.has(options.colorScheme), 'Unsupported color scheme: ' + options.colorScheme);
@@ -372,7 +371,7 @@ export class Page extends EventEmitter {
     return this._state.viewport;
   }
 
-  evaluate: types.Evaluate = (pageFunction, ...args) => {
+  evaluate: types.Evaluate = async (pageFunction, ...args) => {
     return this.mainFrame().evaluate(pageFunction, ...args as any);
   }
 
@@ -392,7 +391,7 @@ export class Page extends EventEmitter {
     return this._screenshotter.screenshotPage(options);
   }
 
-  title(): Promise<string> {
+  async title(): Promise<string> {
     return this.mainFrame().title();
   }
 
@@ -410,39 +409,39 @@ export class Page extends EventEmitter {
     return this._closed;
   }
 
-  click(selector: string, options?: frames.WaitForOptions & input.ClickOptions) {
+  async click(selector: string, options?: frames.WaitForOptions & input.ClickOptions) {
     return this.mainFrame().click(selector, options);
   }
 
-  dblclick(selector: string, options?: frames.WaitForOptions & input.MultiClickOptions) {
+  async dblclick(selector: string, options?: frames.WaitForOptions & input.MultiClickOptions) {
     return this.mainFrame().dblclick(selector, options);
   }
 
-  tripleclick(selector: string, options?: frames.WaitForOptions & input.MultiClickOptions) {
+  async tripleclick(selector: string, options?: frames.WaitForOptions & input.MultiClickOptions) {
     return this.mainFrame().tripleclick(selector, options);
   }
 
-  fill(selector: string, value: string, options?: frames.WaitForOptions) {
+  async fill(selector: string, value: string, options?: frames.WaitForOptions) {
     return this.mainFrame().fill(selector, value, options);
   }
 
-  focus(selector: string, options?: frames.WaitForOptions) {
+  async focus(selector: string, options?: frames.WaitForOptions) {
     return this.mainFrame().focus(selector, options);
   }
 
-  hover(selector: string, options?: frames.WaitForOptions & input.PointerActionOptions) {
+  async hover(selector: string, options?: frames.WaitForOptions & input.PointerActionOptions) {
     return this.mainFrame().hover(selector, options);
   }
 
-  select(selector: string, value: string | dom.ElementHandle | input.SelectOption | string[] | dom.ElementHandle[] | input.SelectOption[] | undefined, options?: frames.WaitForOptions): Promise<string[]> {
+  async select(selector: string, value: string | dom.ElementHandle | input.SelectOption | string[] | dom.ElementHandle[] | input.SelectOption[] | undefined, options?: frames.WaitForOptions): Promise<string[]> {
     return this.mainFrame().select(selector, value, options);
   }
 
-  type(selector: string, text: string, options?: frames.WaitForOptions & { delay?: number }) {
+  async type(selector: string, text: string, options?: frames.WaitForOptions & { delay?: number }) {
     return this.mainFrame().type(selector, text, options);
   }
 
-  waitFor(selectorOrFunctionOrTimeout: (string | number | Function), options: { visible?: boolean; hidden?: boolean; timeout?: number; polling?: string | number; } = {}, ...args: any[]): Promise<js.JSHandle> {
+  async waitFor(selectorOrFunctionOrTimeout: (string | number | Function), options: { visible?: boolean; hidden?: boolean; timeout?: number; polling?: string | number; } = {}, ...args: any[]): Promise<js.JSHandle> {
     return this.mainFrame().waitFor(selectorOrFunctionOrTimeout, options, ...args);
   }
 
diff --git a/webkit.js b/webkit.js
index aa8f1bec1f..37b792ffb2 100644
--- a/webkit.js
+++ b/webkit.js
@@ -14,15 +14,4 @@
  * limitations under the License.
  */
 
-const {helper} = require('./lib/helper');
-const api = require('./lib/api');
-for (const className in api.WebKit) {
-  // Playwright-web excludes certain classes from bundle, e.g. BrowserFetcher.
-  if (typeof api.WebKit[className] === 'function')
-    helper.installAsyncStackHooks(api.WebKit[className]);
-}
-
-const { WKPlaywright } = require('./lib/webkit/wkPlaywright');
-const packageJson = require('./package.json');
-
-module.exports = new WKPlaywright(__dirname, packageJson.playwright.webkit_revision);
+module.exports = require('./index').playwright('webkit');