diff --git a/package.json b/package.json
index 17f31f7b24..38b0354ac8 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,7 @@
   "main": "index.js",
   "playwright": {
     "chromium_revision": "724623",
-    "firefox_revision": "1008",
+    "firefox_revision": "1009",
     "webkit_revision": "1055"
   },
   "scripts": {
diff --git a/src/chromium/crBrowser.ts b/src/chromium/crBrowser.ts
index ee5c98142e..ee1cc50fcc 100644
--- a/src/chromium/crBrowser.ts
+++ b/src/chromium/crBrowser.ts
@@ -69,7 +69,6 @@ export class CRBrowser extends browser.Browser {
   }
 
   _createBrowserContext(contextId: string | null, options: BrowserContextOptions): BrowserContext {
-    let overrides: CROverrides | null = null;
     const context = new BrowserContext({
       pages: async (): Promise<Page[]> => {
         const targets = this._allTargets().filter(target => target.browserContext() === context && target.type() === 'page');
@@ -81,28 +80,7 @@ export class CRBrowser extends browser.Browser {
         const { targetId } = await this._client.send('Target.createTarget', { url: 'about:blank', browserContextId: contextId || undefined });
         const target = this._targets.get(targetId);
         assert(await target._initializedPromise, 'Failed to create target for page');
-        const page = await target.page();
-        const crPage = target._crPage;
-        const session = crPage._client;
-        const promises: Promise<any>[] = [ overrides._applyOverrides(crPage) ];
-        if (options.bypassCSP)
-          promises.push(session.send('Page.setBypassCSP', { enabled: true }));
-        if (options.ignoreHTTPSErrors)
-          promises.push(session.send('Security.setIgnoreCertificateErrors', { ignore: true }));
-        if (options.viewport)
-          promises.push(crPage.setViewport(options.viewport));
-        if (options.javaScriptEnabled === false)
-          promises.push(session.send('Emulation.setScriptExecutionDisabled', { value: true }));
-        if (options.userAgent)
-          crPage._networkManager.setUserAgent(options.userAgent);
-        if (options.mediaType || options.colorScheme) {
-          const features = options.colorScheme ? [{ name: 'prefers-color-scheme', value: options.colorScheme }] : [];
-          promises.push(session.send('Emulation.setEmulatedMedia', { media: options.mediaType || '', features }));
-        }
-        if (options.timezoneId)
-          promises.push(emulateTimezone(session, options.timezoneId));
-        await Promise.all(promises);
-        return page;
+        return target.page();
       },
 
       close: async (): Promise<void> => {
@@ -162,8 +140,7 @@ export class CRBrowser extends browser.Browser {
       }
 
     }, options);
-    overrides = new CROverrides(context);
-    (context as any).overrides = overrides;
+    (context as any).overrides = new CROverrides(context);
     return context;
   }
 
@@ -317,13 +294,3 @@ export class CRBrowser extends browser.Browser {
     return !this._connection._closed;
   }
 }
-
-async function emulateTimezone(session: CRSession, timezoneId: string) {
-  try {
-    await session.send('Emulation.setTimezoneOverride', { timezoneId: timezoneId });
-  } catch (exception) {
-    if (exception.message.includes('Invalid timezone'))
-      throw new Error(`Invalid timezone ID: ${timezoneId}`);
-    throw exception;
-  }
-}
diff --git a/src/chromium/crPage.ts b/src/chromium/crPage.ts
index 33dec12721..b30af7b70c 100644
--- a/src/chromium/crPage.ts
+++ b/src/chromium/crPage.ts
@@ -38,6 +38,7 @@ import { BrowserContext } from '../browserContext';
 import * as types from '../types';
 import * as input from '../input';
 import { ConsoleMessage } from '../console';
+import { CROverrides } from './features/crOverrides';
 
 const UTILITY_WORLD_NAME = '__playwright_utility_world__';
 
@@ -86,13 +87,32 @@ export class CRPage implements PageDelegate {
       this._client.send('Page.getFrameTree'),
     ]);
     this._handleFrameTree(frameTree);
-    await Promise.all([
+    const promises: Promise<any>[] = [
       this._client.send('Log.enable', {}),
       this._client.send('Page.setInterceptFileChooserDialog', {enabled: true}),
       this._client.send('Page.setLifecycleEventsEnabled', { enabled: true }),
       this._client.send('Runtime.enable', {}).then(() => this._ensureIsolatedWorld(UTILITY_WORLD_NAME)),
       this._networkManager.initialize(),
-    ]);
+      ((this._page.browserContext() as any).overrides as CROverrides)._applyOverrides(this),
+    ];
+    const options = this._page.browserContext()._options;
+    if (options.bypassCSP)
+      promises.push(this._client.send('Page.setBypassCSP', { enabled: true }));
+    if (options.ignoreHTTPSErrors)
+      promises.push(this._client.send('Security.setIgnoreCertificateErrors', { ignore: true }));
+    if (options.viewport)
+      promises.push(this.setViewport(options.viewport));
+    if (options.javaScriptEnabled === false)
+      promises.push(this._client.send('Emulation.setScriptExecutionDisabled', { value: true }));
+    if (options.userAgent)
+      this._networkManager.setUserAgent(options.userAgent);
+    if (options.mediaType || options.colorScheme) {
+      const features = options.colorScheme ? [{ name: 'prefers-color-scheme', value: options.colorScheme }] : [];
+      promises.push(this._client.send('Emulation.setEmulatedMedia', { media: options.mediaType || '', features }));
+    }
+    if (options.timezoneId)
+      promises.push(emulateTimezone(this._client, options.timezoneId));
+    await Promise.all(promises);
   }
 
   didClose() {
@@ -488,3 +508,13 @@ export class ChromiumPage extends Page {
 function toRemoteObject(handle: dom.ElementHandle): Protocol.Runtime.RemoteObject {
   return handle._remoteObject as Protocol.Runtime.RemoteObject;
 }
+
+async function emulateTimezone(session: CRSession, timezoneId: string) {
+  try {
+    await session.send('Emulation.setTimezoneOverride', { timezoneId: timezoneId });
+  } catch (exception) {
+    if (exception.message.includes('Invalid timezone'))
+      throw new Error(`Invalid timezone ID: ${timezoneId}`);
+    throw exception;
+  }
+}
diff --git a/src/firefox/ffBrowser.ts b/src/firefox/ffBrowser.ts
index 651ec3dee0..211ab1eb30 100644
--- a/src/firefox/ffBrowser.ts
+++ b/src/firefox/ffBrowser.ts
@@ -155,21 +155,7 @@ export class FFBrowser extends browser.Browser {
           browserContextId: browserContextId || undefined
         });
         const target = this._targets.get(targetId);
-        const page = await target.page();
-        const session = target._ffPage._session;
-        const promises: Promise<any>[] = [];
-        if (options.viewport)
-          promises.push(page._delegate.setViewport(options.viewport));
-        if (options.bypassCSP)
-          promises.push(session.send('Page.setBypassCSP', { enabled: true }));
-        if (options.javaScriptEnabled === false)
-          promises.push(session.send('Page.setJavascriptEnabled', { enabled: false }));
-        if (options.userAgent)
-          promises.push(session.send('Page.setUserAgent', { userAgent: options.userAgent }));
-        if (options.mediaType || options.colorScheme)
-          promises.push(session.send('Page.setEmulatedMedia', { type: options.mediaType, colorScheme: options.colorScheme }));
-        await Promise.all(promises);
-        return page;
+        return target.page();
       },
 
       close: async (): Promise<void> => {
diff --git a/src/firefox/ffPage.ts b/src/firefox/ffPage.ts
index bc8330b545..318bf2e062 100644
--- a/src/firefox/ffPage.ts
+++ b/src/firefox/ffPage.ts
@@ -68,12 +68,24 @@ export class FFPage implements PageDelegate {
   }
 
   async _initialize() {
-    await Promise.all([
+    const promises: Promise<any>[] = [
       this._session.send('Runtime.enable'),
       this._session.send('Network.enable'),
       this._session.send('Page.enable'),
       this._session.send('Page.setInterceptFileChooserDialog', { enabled: true })
-    ]);
+    ];
+    const options = this._page.browserContext()._options;
+    if (options.viewport)
+      promises.push(this.setViewport(options.viewport));
+    if (options.bypassCSP)
+      promises.push(this._session.send('Page.setBypassCSP', { enabled: true }));
+    if (options.javaScriptEnabled === false)
+      promises.push(this._session.send('Page.setJavascriptEnabled', { enabled: false }));
+    if (options.userAgent)
+      promises.push(this._session.send('Page.setUserAgent', { userAgent: options.userAgent }));
+    if (options.mediaType || options.colorScheme)
+      promises.push(this._session.send('Page.setEmulatedMedia', { type: options.mediaType, colorScheme: options.colorScheme }));
+    await Promise.all(promises);
   }
 
   _onExecutionContextCreated({executionContextId, auxData}) {
diff --git a/src/webkit/wkExecutionContext.ts b/src/webkit/wkExecutionContext.ts
index 678eae53c0..ba5b4798f8 100644
--- a/src/webkit/wkExecutionContext.ts
+++ b/src/webkit/wkExecutionContext.ts
@@ -30,6 +30,7 @@ export class WKExecutionContext implements js.ExecutionContextDelegate {
   _contextId: number;
   private _contextDestroyedCallback: () => void;
   private _executionContextDestroyedPromise: Promise<unknown>;
+  _jsonObjectId: Protocol.Runtime.RemoteObjectId | undefined;
 
   constructor(client: WKTargetSession, contextPayload: Protocol.Runtime.ExecutionContextDescription) {
     this._session = client;
@@ -218,7 +219,7 @@ export class WKExecutionContext implements js.ExecutionContextDelegate {
   }
 
   private _returnObjectByValue(objectId: Protocol.Runtime.RemoteObjectId) {
-    const serializeFunction = function() {
+    const serializeFunction = function(JSON: { stringify: (o: any) => string }) {
       try {
         return JSON.stringify(this);
       } catch (e) {
@@ -231,6 +232,7 @@ export class WKExecutionContext implements js.ExecutionContextDelegate {
       // Serialize object using standard JSON implementation to correctly pass 'undefined'.
       functionDeclaration: serializeFunction + '\n' + suffix + '\n',
       objectId: objectId,
+      arguments: [ { objectId: this._jsonObjectId } ],
       returnByValue: true
     }).catch(e => {
       if (isSwappedOutError(e))
diff --git a/src/webkit/wkPage.ts b/src/webkit/wkPage.ts
index ddc167bcc6..df8bddbbcd 100644
--- a/src/webkit/wkPage.ts
+++ b/src/webkit/wkPage.ts
@@ -36,6 +36,8 @@ import { PNG } from 'pngjs';
 
 const UTILITY_WORLD_NAME = '__playwright_utility_world__';
 const BINDING_CALL_MESSAGE = '__playwright_binding_call__';
+const JSON_CALL_MESSAGE = '__playwright_json_call__';
+const JSON_SAVE_SCRIPT = `console.debug('${JSON_CALL_MESSAGE}', JSON)`;
 
 export class WKPage implements PageDelegate {
   readonly rawMouse: RawMouseImpl;
@@ -47,7 +49,7 @@ export class WKPage implements PageDelegate {
   private readonly _contextIdToContext: Map<number, dom.FrameExecutionContext>;
   private _isolatedWorlds: Set<string>;
   private _sessionListeners: RegisteredListener[] = [];
-  private readonly _bootstrapScripts: string[] = [];
+  private readonly _bootstrapScripts: string[] = [ JSON_SAVE_SCRIPT ];
 
   constructor(browser: WKBrowser, browserContext: BrowserContext) {
     this._browser = browser;
@@ -70,7 +72,7 @@ export class WKPage implements PageDelegate {
     this._isolatedWorlds = new Set();
     // New bootstrap scripts may have been added during provisional load, push them
     // again to be on the safe side.
-    if (this._setBootstrapScripts.length)
+    if (this._bootstrapScripts.length)
       this._setBootstrapScripts(session).catch(e => debugError(e));
   }
 
@@ -107,6 +109,8 @@ export class WKPage implements PageDelegate {
       promises.push(this._setExtraHTTPHeaders(session, this._page._state.extraHTTPHeaders));
     if (this._page._state.viewport)
       promises.push(WKPage._setViewport(session, this._page._state.viewport));
+    if (contextOptions.javaScriptEnabled !== false)
+      promises.push(session.send('Page.setBootstrapScript', { source: JSON_SAVE_SCRIPT }));
     await Promise.all(promises);
   }
 
@@ -217,6 +221,12 @@ export class WKPage implements PageDelegate {
       this._page._onBindingCalled(parameters[2].value, context);
       return;
     }
+    if (level === 'debug' && parameters && parameters[0].value === JSON_CALL_MESSAGE) {
+      const parsedObjectId = JSON.parse(parameters[1].objectId);
+      const context = this._contextIdToContext.get(parsedObjectId.injectedScriptId);
+      (context._delegate as WKExecutionContext)._jsonObjectId = parameters[1].objectId;
+      return;
+    }
     let derivedType: string = type;
     if (type === 'log')
       derivedType = level;
diff --git a/test/evaluation.spec.js b/test/evaluation.spec.js
index 8859f6ce95..7fd2730575 100644
--- a/test/evaluation.spec.js
+++ b/test/evaluation.spec.js
@@ -259,10 +259,10 @@ module.exports.describe = function({testRunner, expect, FFOX, CHROME, WEBKIT}) {
       })).catch(e => error = e);
       expect(error.message).toContain('Error in promise');
     });
-    it.skip(FFOX || WEBKIT)('should work even when JSON is set to null', async({page, server}) => {
+    it('should work even when JSON is set to null', async ({ page }) => {
       await page.evaluate(() => { window.JSON.stringify = null; window.JSON = null; });
       const result = await page.evaluate(() => ({abc: 123}));
-      expect(result).toEqual({abc: 123}); 
+      expect(result).toEqual({abc: 123});
     })
   });