diff --git a/experimental/puppeteer-firefox/lib/Launcher.js b/experimental/puppeteer-firefox/lib/Launcher.js
index 9b1a1c97..d0fdd696 100644
--- a/experimental/puppeteer-firefox/lib/Launcher.js
+++ b/experimental/puppeteer-firefox/lib/Launcher.js
@@ -32,6 +32,11 @@ const removeFolderAsync = util.promisify(removeFolder);
 
 const FIREFOX_PROFILE_PATH = path.join(os.tmpdir(), 'puppeteer_firefox_profile-');
 
+const DEFAULT_ARGS = [
+  '-no-remote',
+  '-foreground',
+];
+
 /**
  * @internal
  */
@@ -41,15 +46,34 @@ class Launcher {
     this._preferredRevision = preferredRevision;
   }
 
+  defaultArgs(options = {}) {
+    const {
+      headless = true,
+      args = [],
+      userDataDir = null,
+    } = options;
+    const firefoxArguments = [...DEFAULT_ARGS];
+    if (userDataDir)
+      firefoxArguments.push('-profile', userDataDir);
+    if (headless)
+      firefoxArguments.push('-headless');
+    firefoxArguments.push(...args);
+    if (args.every(arg => arg.startsWith('-')))
+      firefoxArguments.push('about:blank');
+    return firefoxArguments;
+  }
+
   /**
    * @param {Object} options
    * @return {!Promise<!Browser>}
    */
   async launch(options = {}) {
     const {
+      ignoreDefaultArgs = false,
       args = [],
       dumpio = false,
-      executablePath = this.executablePath(),
+      executablePath = null,
+      env = process.env,
       handleSIGHUP = true,
       handleSIGINT = true,
       handleSIGTERM = true,
@@ -57,25 +81,36 @@ class Launcher {
       headless = true,
       defaultViewport = {width: 800, height: 600},
       slowMo = 0,
+      timeout = 30000,
     } = options;
 
-    const firefoxArguments = args.slice();
-    firefoxArguments.push('-no-remote');
-    firefoxArguments.push('-juggler', '0');
-    firefoxArguments.push('-foreground');
-    if (headless)
-      firefoxArguments.push('-headless');
+    const firefoxArguments = [];
+    if (!ignoreDefaultArgs)
+      firefoxArguments.push(...this.defaultArgs(options));
+    else if (Array.isArray(ignoreDefaultArgs))
+      firefoxArguments.push(...this.defaultArgs(options).filter(arg => !ignoreDefaultArgs.includes(arg)));
+    else
+      firefoxArguments.push(...args);
+
+    if (!firefoxArguments.includes('-juggler'))
+      firefoxArguments.push('-juggler', '0');
+
     let temporaryProfileDir = null;
-    if (!firefoxArguments.some(arg => arg.startsWith('-profile') || arg.startsWith('--profile'))) {
+    if (!firefoxArguments.includes('-profile') && !firefoxArguments.includes('--profile')) {
       temporaryProfileDir = await mkdtempAsync(FIREFOX_PROFILE_PATH);
       firefoxArguments.push(`-profile`, temporaryProfileDir);
     }
-    if (firefoxArguments.every(arg => arg.startsWith('--') || arg.startsWith('-')))
-      firefoxArguments.push('about:blank');
 
+    let firefoxExecutable = executablePath;
+    if (!firefoxExecutable) {
+      const {missingText, executablePath} = this._resolveExecutablePath();
+      if (missingText)
+        throw new Error(missingText);
+      firefoxExecutable = executablePath;
+    }
     const stdio = ['pipe', 'pipe', 'pipe'];
     const firefoxProcess = childProcess.spawn(
-        executablePath,
+        firefoxExecutable,
         firefoxArguments,
         {
           // On non-windows platforms, `detached: false` makes child process a leader of a new
@@ -85,9 +120,9 @@ class Launcher {
           stdio,
           // On linux Juggler ships the libstdc++ it was linked against.
           env: os.platform() === 'linux' ? {
-            ...process.env,
-            LD_LIBRARY_PATH: `${path.dirname(executablePath)}:${process.env.LD_LIBRARY_PATH}`,
-          } : process.env,
+            ...env,
+            LD_LIBRARY_PATH: `${path.dirname(firefoxExecutable)}:${process.env.LD_LIBRARY_PATH}`,
+          } : env,
         }
     );
 
@@ -115,16 +150,16 @@ class Launcher {
     if (handleSIGINT)
       listeners.push(helper.addEventListener(process, 'SIGINT', () => { killFirefox(); process.exit(130); }));
     if (handleSIGTERM)
-      listeners.push(helper.addEventListener(process, 'SIGTERM', killFirefox));
+      listeners.push(helper.addEventListener(process, 'SIGTERM', gracefullyCloseFirefox));
     if (handleSIGHUP)
-      listeners.push(helper.addEventListener(process, 'SIGHUP', killFirefox));
+      listeners.push(helper.addEventListener(process, 'SIGHUP', gracefullyCloseFirefox));
     /** @type {?Connection} */
     let connection = null;
     try {
-      const url = await waitForWSEndpoint(firefoxProcess, 30000);
+      const url = await waitForWSEndpoint(firefoxProcess, timeout);
       const transport = await WebSocketTransport.create(url);
       connection = new Connection(url, transport, slowMo);
-      const browser = await Browser.create(connection, defaultViewport, firefoxProcess, killFirefox);
+      const browser = await Browser.create(connection, defaultViewport, firefoxProcess, gracefullyCloseFirefox);
       if (ignoreHTTPSErrors)
         await connection.send('Browser.setIgnoreHTTPSErrors', {enabled: true});
       await browser.waitForTarget(t => t.type() === 'page');
@@ -134,6 +169,19 @@ class Launcher {
       throw e;
     }
 
+    function gracefullyCloseFirefox() {
+      helper.removeEventListeners(listeners);
+      if (temporaryProfileDir) {
+        killFirefox();
+      } else if (connection) {
+        connection.send('Browser.close').catch(error => {
+          debugError(error);
+          killFirefox();
+        });
+      }
+      return waitForFirefoxToClose;
+    }
+
     // This method has to be sync to be used as 'exit' event handler.
     function killFirefox() {
       helper.removeEventListeners(listeners);
@@ -179,9 +227,14 @@ class Launcher {
    * @return {string}
    */
   executablePath() {
+    return this._resolveExecutablePath().executablePath;
+  }
+
+  _resolveExecutablePath() {
     const browserFetcher = new BrowserFetcher(this._projectRoot, { product: 'firefox' });
     const revisionInfo = browserFetcher.revisionInfo(this._preferredRevision);
-    return revisionInfo.executablePath;
+    const missingText = !revisionInfo.local ? `Firefox revision is not downloaded. Run "npm install" or "yarn install"` : null;
+    return {executablePath: revisionInfo.executablePath, missingText};
   }
 }
 
diff --git a/experimental/puppeteer-firefox/lib/NavigationWatchdog.js b/experimental/puppeteer-firefox/lib/NavigationWatchdog.js
index 8eb8b20b..2d5a8837 100644
--- a/experimental/puppeteer-firefox/lib/NavigationWatchdog.js
+++ b/experimental/puppeteer-firefox/lib/NavigationWatchdog.js
@@ -62,6 +62,7 @@ class NavigationWatchdog {
 
     const check = this._checkNavigationComplete.bind(this);
     this._eventListeners = [
+      helper.addEventListener(session, Events.JugglerSession.Disconnected, () => this._resolveCallback(new Error('Navigation failed because browser has disconnected!'))),
       helper.addEventListener(session, 'Page.eventFired', check),
       helper.addEventListener(session, 'Page.frameAttached', check),
       helper.addEventListener(session, 'Page.frameDetached', check),
diff --git a/experimental/puppeteer-firefox/lib/Puppeteer.js b/experimental/puppeteer-firefox/lib/Puppeteer.js
index 031aac34..e1bceaac 100644
--- a/experimental/puppeteer-firefox/lib/Puppeteer.js
+++ b/experimental/puppeteer-firefox/lib/Puppeteer.js
@@ -26,6 +26,10 @@ class Puppeteer {
   executablePath() {
     return this._launcher.executablePath();
   }
+
+  defaultArgs(options) {
+    return this._launcher.defaultArgs(options);
+  }
 }
 
 module.exports = {Puppeteer};
diff --git a/experimental/puppeteer-firefox/misc/puppeteer.cfg b/experimental/puppeteer-firefox/misc/puppeteer.cfg
index 2d886e40..24527c68 100644
--- a/experimental/puppeteer-firefox/misc/puppeteer.cfg
+++ b/experimental/puppeteer-firefox/misc/puppeteer.cfg
@@ -57,8 +57,8 @@ pref("browser.startup.homepage_override.mstone", "ignore");
 // Disable browser animations (tabs, fullscreen, sliding alerts)
 pref("toolkit.cosmeticAnimations.enabled", false);
 
-// Do not close the window when the last tab gets closed
-pref("browser.tabs.closeWindowWithLastTab", false);
+// Close the window when the last tab gets closed
+pref("browser.tabs.closeWindowWithLastTab", true);
 
 // Do not allow background tabs to be zombified on Android, otherwise for
 // tests that open additional tabs, the test harness tab itself might get
diff --git a/lib/Launcher.js b/lib/Launcher.js
index 4b731a7c..de612c79 100644
--- a/lib/Launcher.js
+++ b/lib/Launcher.js
@@ -174,32 +174,13 @@ class Launcher {
         connection = new Connection('', transport, slowMo);
       }
       const browser = await Browser.create(connection, [], ignoreHTTPSErrors, defaultViewport, chromeProcess, gracefullyCloseChrome);
-      await ensureInitialPage(browser);
+      await browser.waitForTarget(t => t.type() === 'page');
       return browser;
     } catch (e) {
       killChrome();
       throw e;
     }
 
-    /**
-     * @param {!Browser} browser
-     */
-    async function ensureInitialPage(browser) {
-      // Wait for initial page target to be created.
-      if (browser.targets().find(target => target.type() === 'page'))
-        return;
-
-      let initialPageCallback;
-      const initialPagePromise = new Promise(resolve => initialPageCallback = resolve);
-      const listeners = [helper.addEventListener(browser, 'targetcreated', target => {
-        if (target.type() === 'page')
-          initialPageCallback();
-      })];
-
-      await initialPagePromise;
-      helper.removeEventListeners(listeners);
-    }
-
     /**
      * @return {Promise}
      */
diff --git a/test/launcher.spec.js b/test/launcher.spec.js
index 1342b978..0f312840 100644
--- a/test/launcher.spec.js
+++ b/test/launcher.spec.js
@@ -24,7 +24,7 @@ const statAsync = helper.promisify(fs.stat);
 const TMP_FOLDER = path.join(os.tmpdir(), 'pptr_tmp_folder-');
 const utils = require('./utils');
 
-module.exports.addTests = function({testRunner, expect, defaultBrowserOptions, puppeteer}) {
+module.exports.addTests = function({testRunner, expect, defaultBrowserOptions, puppeteer, CHROME}) {
   const {describe, xdescribe, fdescribe, describe_fails_ffox} = testRunner;
   const {it, fit, xit, it_fails_ffox} = testRunner;
   const {beforeAll, beforeEach, afterAll, afterEach} = testRunner;
@@ -59,7 +59,7 @@ module.exports.addTests = function({testRunner, expect, defaultBrowserOptions, p
         await rmAsync(downloadsFolder);
       });
     });
-    describe_fails_ffox('Browser.disconnect', function() {
+    describe('Browser.disconnect', function() {
       it('should reject navigation when browser closes', async({server}) => {
         server.setRoute('/one-style.css', () => {});
         const browser = await puppeteer.launch(defaultBrowserOptions);
@@ -80,7 +80,7 @@ module.exports.addTests = function({testRunner, expect, defaultBrowserOptions, p
         const watchdog = page.waitForSelector('div', {timeout: 60000}).catch(e => e);
         await remote.disconnect();
         const error = await watchdog;
-        expect(error.message).toBe('Protocol error (Runtime.callFunctionOn): Session closed. Most likely the page has been closed.');
+        expect(error.message).toContain('Protocol error');
         await browser.close();
       });
     });
@@ -94,13 +94,13 @@ module.exports.addTests = function({testRunner, expect, defaultBrowserOptions, p
         await neverResolves;
         expect(error.message).toContain('Protocol error');
       });
-      it_fails_ffox('should reject if executable path is invalid', async({server}) => {
+      it('should reject if executable path is invalid', async({server}) => {
         let waitError = null;
         const options = Object.assign({}, defaultBrowserOptions, {executablePath: 'random-invalid-path'});
         await puppeteer.launch(options).catch(e => waitError = e);
-        expect(waitError.message.startsWith('Failed to launch chrome! spawn random-invalid-path ENOENT')).toBe(true);
+        expect(waitError.message).toContain('Failed to launch');
       });
-      it_fails_ffox('userDataDir option', async({server}) => {
+      it('userDataDir option', async({server}) => {
         const userDataDir = await mkdtempAsync(TMP_FOLDER);
         const options = Object.assign({userDataDir}, defaultBrowserOptions);
         const browser = await puppeteer.launch(options);
@@ -112,10 +112,21 @@ module.exports.addTests = function({testRunner, expect, defaultBrowserOptions, p
         // This might throw. See https://github.com/GoogleChrome/puppeteer/issues/2778
         await rmAsync(userDataDir).catch(e => {});
       });
-      it_fails_ffox('userDataDir argument', async({server}) => {
+      it('userDataDir argument', async({server}) => {
         const userDataDir = await mkdtempAsync(TMP_FOLDER);
         const options = Object.assign({}, defaultBrowserOptions);
-        options.args = [`--user-data-dir=${userDataDir}`].concat(options.args || []);
+        if (CHROME) {
+          options.args = [
+            ...(defaultBrowserOptions.args || []),
+            `--user-data-dir=${userDataDir}`
+          ];
+        } else {
+          options.args = [
+            ...(defaultBrowserOptions.args || []),
+            `-profile`,
+            userDataDir,
+          ];
+        }
         const browser = await puppeteer.launch(options);
         expect(fs.readdirSync(userDataDir).length).toBeGreaterThan(0);
         await browser.close();
@@ -123,7 +134,7 @@ module.exports.addTests = function({testRunner, expect, defaultBrowserOptions, p
         // This might throw. See https://github.com/GoogleChrome/puppeteer/issues/2778
         await rmAsync(userDataDir).catch(e => {});
       });
-      it_fails_ffox('userDataDir option should restore state', async({server}) => {
+      it('userDataDir option should restore state', async({server}) => {
         const userDataDir = await mkdtempAsync(TMP_FOLDER);
         const options = Object.assign({userDataDir}, defaultBrowserOptions);
         const browser = await puppeteer.launch(options);
@@ -140,7 +151,7 @@ module.exports.addTests = function({testRunner, expect, defaultBrowserOptions, p
         // This might throw. See https://github.com/GoogleChrome/puppeteer/issues/2778
         await rmAsync(userDataDir).catch(e => {});
       });
-      it_fails_ffox('userDataDir option should restore cookies', async({server}) => {
+      it('userDataDir option should restore cookies', async({server}) => {
         const userDataDir = await mkdtempAsync(TMP_FOLDER);
         const options = Object.assign({userDataDir}, defaultBrowserOptions);
         const browser = await puppeteer.launch(options);
@@ -157,11 +168,18 @@ module.exports.addTests = function({testRunner, expect, defaultBrowserOptions, p
         // This might throw. See https://github.com/GoogleChrome/puppeteer/issues/2778
         await rmAsync(userDataDir).catch(e => {});
       });
-      it_fails_ffox('should return the default chrome arguments', async() => {
-        expect(puppeteer.defaultArgs()).toContain('--no-first-run');
-        expect(puppeteer.defaultArgs()).toContain('--headless');
-        expect(puppeteer.defaultArgs({headless: false})).not.toContain('--headless');
-        expect(puppeteer.defaultArgs({userDataDir: 'foo'})).toContain('--user-data-dir=foo');
+      it('should return the default arguments', async() => {
+        if (CHROME) {
+          expect(puppeteer.defaultArgs()).toContain('--no-first-run');
+          expect(puppeteer.defaultArgs()).toContain('--headless');
+          expect(puppeteer.defaultArgs({headless: false})).not.toContain('--headless');
+          expect(puppeteer.defaultArgs({userDataDir: 'foo'})).toContain('--user-data-dir=foo');
+        } else {
+          expect(puppeteer.defaultArgs()).toContain('-headless');
+          expect(puppeteer.defaultArgs({headless: false})).not.toContain('-headless');
+          expect(puppeteer.defaultArgs({userDataDir: 'foo'})).toContain('-profile');
+          expect(puppeteer.defaultArgs({userDataDir: 'foo'})).toContain('foo');
+        }
       });
       it('should dump browser process stderr', async({server}) => {
         const dumpioTextToLog = 'MAGIC_DUMPIO_TEST';
@@ -196,34 +214,6 @@ module.exports.addTests = function({testRunner, expect, defaultBrowserOptions, p
           process.kill(res.pid);
         await Promise.all(promises);
       });
-      it_fails_ffox('should support the pipe option', async() => {
-        const options = Object.assign({pipe: true}, defaultBrowserOptions);
-        const browser = await puppeteer.launch(options);
-        expect((await browser.pages()).length).toBe(1);
-        expect(browser.wsEndpoint()).toBe('');
-        const page = await browser.newPage();
-        expect(await page.evaluate('11 * 11')).toBe(121);
-        await page.close();
-        await browser.close();
-      });
-      it_fails_ffox('should support the pipe argument', async() => {
-        const options = Object.assign({}, defaultBrowserOptions);
-        options.args = ['--remote-debugging-pipe'].concat(options.args || []);
-        const browser = await puppeteer.launch(options);
-        expect(browser.wsEndpoint()).toBe('');
-        const page = await browser.newPage();
-        expect(await page.evaluate('11 * 11')).toBe(121);
-        await page.close();
-        await browser.close();
-      });
-      it_fails_ffox('should fire "disconnected" when closing with pipe', async() => {
-        const options = Object.assign({pipe: true}, defaultBrowserOptions);
-        const browser = await puppeteer.launch(options);
-        const disconnectedEventPromise = new Promise(resolve => browser.once('disconnected', resolve));
-        // Emulate user exiting browser.
-        browser.process().kill();
-        await disconnectedEventPromise;
-      });
       it('should work with no default arguments', async() => {
         const options = Object.assign({}, defaultBrowserOptions);
         options.ignoreDefaultArgs = true;
@@ -233,7 +223,7 @@ module.exports.addTests = function({testRunner, expect, defaultBrowserOptions, p
         await page.close();
         await browser.close();
       });
-      it_fails_ffox('should filter out ignored default arguments', async() => {
+      it('should filter out ignored default arguments', async() => {
         // Make sure we launch with `--enable-automation` by default.
         const defaultArgs = puppeteer.defaultArgs();
         const browser = await puppeteer.launch(Object.assign({}, defaultBrowserOptions, {
@@ -253,15 +243,14 @@ module.exports.addTests = function({testRunner, expect, defaultBrowserOptions, p
         await browser.close();
       });
       it_fails_ffox('should have custom url when launching browser', async function({server}) {
-        const customUrl = server.PREFIX + '/empty.html';
         const options = Object.assign({}, defaultBrowserOptions);
-        options.args = [customUrl].concat(options.args || []);
+        options.args = [server.EMPTY_PAGE].concat(options.args || []);
         const browser = await puppeteer.launch(options);
         const pages = await browser.pages();
         expect(pages.length).toBe(1);
-        if (pages[0].url() !== customUrl)
+        if (pages[0].url() !== server.EMPTY_PAGE)
           await pages[0].waitForNavigation();
-        expect(pages[0].url()).toBe(customUrl);
+        expect(pages[0].url()).toBe(server.EMPTY_PAGE);
         await browser.close();
       });
       it('should set the default viewport', async() => {
@@ -300,6 +289,85 @@ module.exports.addTests = function({testRunner, expect, defaultBrowserOptions, p
         await browser.close();
       });
     });
+    // "browserURL" is a chrome-only option.
+    (CHROME ? describe : xdescribe)('|browserURL| option', function() {
+      it('should be able to connect using browserUrl, with and without trailing slash', async({server}) => {
+        const originalBrowser = await puppeteer.launch(Object.assign({}, defaultBrowserOptions, {
+          args: ['--remote-debugging-port=21222']
+        }));
+        const browserURL = 'http://127.0.0.1:21222';
+
+        const browser1 = await puppeteer.connect({browserURL});
+        const page1 = await browser1.newPage();
+        expect(await page1.evaluate(() => 7 * 8)).toBe(56);
+        browser1.disconnect();
+
+        const browser2 = await puppeteer.connect({browserURL: browserURL + '/'});
+        const page2 = await browser2.newPage();
+        expect(await page2.evaluate(() => 8 * 7)).toBe(56);
+        browser2.disconnect();
+        originalBrowser.close();
+      });
+      it('should throw when using both browserWSEndpoint and browserURL', async({server}) => {
+        const originalBrowser = await puppeteer.launch(Object.assign({}, defaultBrowserOptions, {
+          args: ['--remote-debugging-port=21222']
+        }));
+        const browserURL = 'http://127.0.0.1:21222';
+
+        let error = null;
+        await puppeteer.connect({browserURL, browserWSEndpoint: originalBrowser.wsEndpoint()}).catch(e => error = e);
+        expect(error.message).toContain('Exactly one of browserWSEndpoint, browserURL or transport');
+
+        originalBrowser.close();
+      });
+      it('should throw when trying to connect to non-existing browser', async({server}) => {
+        const originalBrowser = await puppeteer.launch(Object.assign({}, defaultBrowserOptions, {
+          args: ['--remote-debugging-port=21222']
+        }));
+        const browserURL = 'http://127.0.0.1:32333';
+
+        let error = null;
+        await puppeteer.connect({browserURL}).catch(e => error = e);
+        if (CHROME)
+          expect(error.message).toContain('Failed to fetch browser webSocket url from');
+        else
+          expect(error.message).toContain('Invalid URL');
+
+        originalBrowser.close();
+      });
+    });
+
+    // "pipe" is a chrome-only feature.
+    (CHROME ? describe : xdescribe)('|pipe| option', function() {
+      it('should support the pipe option', async() => {
+        const options = Object.assign({pipe: true}, defaultBrowserOptions);
+        const browser = await puppeteer.launch(options);
+        expect((await browser.pages()).length).toBe(1);
+        expect(browser.wsEndpoint()).toBe('');
+        const page = await browser.newPage();
+        expect(await page.evaluate('11 * 11')).toBe(121);
+        await page.close();
+        await browser.close();
+      });
+      it('should support the pipe argument', async() => {
+        const options = Object.assign({}, defaultBrowserOptions);
+        options.args = ['--remote-debugging-pipe'].concat(options.args || []);
+        const browser = await puppeteer.launch(options);
+        expect(browser.wsEndpoint()).toBe('');
+        const page = await browser.newPage();
+        expect(await page.evaluate('11 * 11')).toBe(121);
+        await page.close();
+        await browser.close();
+      });
+      it('should fire "disconnected" when closing with pipe', async() => {
+        const options = Object.assign({pipe: true}, defaultBrowserOptions);
+        const browser = await puppeteer.launch(options);
+        const disconnectedEventPromise = new Promise(resolve => browser.once('disconnected', resolve));
+        // Emulate user exiting browser.
+        browser.process().kill();
+        await disconnectedEventPromise;
+      });
+    });
     describe('Puppeteer.connect', function() {
       it('should be able to connect multiple times to the same browser', async({server}) => {
         const originalBrowser = await puppeteer.launch(defaultBrowserOptions);
@@ -359,47 +427,6 @@ module.exports.addTests = function({testRunner, expect, defaultBrowserOptions, p
         expect(await restoredPage.evaluate(() => 7 * 8)).toBe(56);
         await browser.close();
       });
-      it_fails_ffox('should be able to connect using browserUrl, with and without trailing slash', async({server}) => {
-        const originalBrowser = await puppeteer.launch(Object.assign({}, defaultBrowserOptions, {
-          args: ['--remote-debugging-port=21222']
-        }));
-        const browserURL = 'http://127.0.0.1:21222';
-
-        const browser1 = await puppeteer.connect({browserURL});
-        const page1 = await browser1.newPage();
-        expect(await page1.evaluate(() => 7 * 8)).toBe(56);
-        browser1.disconnect();
-
-        const browser2 = await puppeteer.connect({browserURL: browserURL + '/'});
-        const page2 = await browser2.newPage();
-        expect(await page2.evaluate(() => 8 * 7)).toBe(56);
-        browser2.disconnect();
-        originalBrowser.close();
-      });
-      it_fails_ffox('should throw when using both browserWSEndpoint and browserURL', async({server}) => {
-        const originalBrowser = await puppeteer.launch(Object.assign({}, defaultBrowserOptions, {
-          args: ['--remote-debugging-port=21222']
-        }));
-        const browserURL = 'http://127.0.0.1:21222';
-
-        let error = null;
-        await puppeteer.connect({browserURL, browserWSEndpoint: originalBrowser.wsEndpoint()}).catch(e => error = e);
-        expect(error.message).toContain('Exactly one of browserWSEndpoint, browserURL or transport');
-
-        originalBrowser.close();
-      });
-      it_fails_ffox('should throw when trying to connect to non-existing browser', async({server}) => {
-        const originalBrowser = await puppeteer.launch(Object.assign({}, defaultBrowserOptions, {
-          args: ['--remote-debugging-port=21222']
-        }));
-        const browserURL = 'http://127.0.0.1:32333';
-
-        let error = null;
-        await puppeteer.connect({browserURL}).catch(e => error = e);
-        expect(error.message).toContain('Failed to fetch browser webSocket url from');
-
-        originalBrowser.close();
-      });
     });
     describe('Puppeteer.executablePath', function() {
       it('should work', async({server}) => {