diff --git a/src/webkit/wkPage.ts b/src/webkit/wkPage.ts
index 140ccc71a2..a6af66fa19 100644
--- a/src/webkit/wkPage.ts
+++ b/src/webkit/wkPage.ts
@@ -89,19 +89,23 @@ export class WKPage implements PageDelegate {
 
   // This method is called for provisional targets as well. The session passed as the parameter
   // may be different from the current session and may be destroyed without becoming current.
-  async _initializeSession(session: WKSession, isProvisional: boolean) {
+  async _initializeSession(session: WKSession) {
+    const isProvisional = this._session !== session;
     const promises : Promise<any>[] = [
       // Page agent must be enabled before Runtime.
-      session.send('Page.enable'),
-      session.send('Page.getResourceTree').then(({frameTree}) => this._handleFrameTree(frameTree)),
-      // Resource tree should be received before first execution context.
-      session.send('Runtime.enable'),
-      session.send('Page.createIsolatedWorld', { name: UTILITY_WORLD_NAME, source: `//# sourceURL=${EVALUATION_SCRIPT_URL}` }),
-      session.send('Console.enable'),
-      session.send('Page.setInterceptFileChooserDialog', { enabled: true }),
-      this._networkManager.initializeSession(session, this._page._state.interceptNetwork, this._page._state.offlineMode),
-      this._workers.initializeSession(session),
+      session.send('Page.enable')
     ];
+    if (!isProvisional)
+      promises.push(session.send('Page.getResourceTree').then(({frameTree}) => this._handleFrameTree(frameTree)));
+    promises.push(
+        // Resource tree should be received before first execution context.
+        session.send('Runtime.enable'),
+        session.send('Page.createIsolatedWorld', { name: UTILITY_WORLD_NAME, source: `//# sourceURL=${EVALUATION_SCRIPT_URL}` }),
+        session.send('Console.enable'),
+        session.send('Page.setInterceptFileChooserDialog', { enabled: true }),
+        this._networkManager.initializeSession(session, this._page._state.interceptNetwork, this._page._state.offlineMode),
+        this._workers.initializeSession(session)
+    );
     const contextOptions = this._page.browserContext()._options;
     if (contextOptions.userAgent)
       promises.push(session.send('Page.overrideUserAgent', { value: contextOptions.userAgent }));
@@ -186,7 +190,10 @@ export class WKPage implements PageDelegate {
   }
 
   _onFrameNavigated(framePayload: Protocol.Page.Frame, initial: boolean) {
-    const frame = this._page._frameManager.frame(framePayload.id);
+    let frame = this._page._frameManager.frame(framePayload.id);
+    const newProcessMainFrame = !frame && !framePayload.parentId;
+    if (newProcessMainFrame)
+      frame = this._page._frameManager.mainFrame();
     for (const [contextId, context] of this._contextIdToContext) {
       if (context.frame === frame) {
         (context._delegate as WKExecutionContext)._dispose();
@@ -194,6 +201,8 @@ export class WKPage implements PageDelegate {
         frame._contextDestroyed(context);
       }
     }
+    if (newProcessMainFrame)
+      this._onFrameAttached(framePayload.id, null);
     this._page._frameManager.frameCommittedNewDocumentNavigation(framePayload.id, framePayload.url, framePayload.name || '', framePayload.loaderId, initial);
   }
 
diff --git a/src/webkit/wkPageProxy.ts b/src/webkit/wkPageProxy.ts
index f01e1971b2..b9ab535bda 100644
--- a/src/webkit/wkPageProxy.ts
+++ b/src/webkit/wkPageProxy.ts
@@ -22,17 +22,16 @@ import { WKSession } from './wkConnection';
 import { WKPage } from './wkPage';
 import { RegisteredListener, helper, assert, debugError } from '../helper';
 import { Events } from '../events';
+import { WKProvisionalPage } from './wkProvisionalPage';
 
-// We keep provisional messages on the session instace until provisional
-// target is committed. Non-provisional target (there should be just one)
-// has undefined instead.
-const provisionalMessagesSymbol = Symbol('provisionalMessages');
+const isPovisionalSymbol = Symbol('isPovisional');
 
 export class WKPageProxy {
   private readonly _pageProxySession: WKSession;
   readonly _browserContext: BrowserContext;
   private _pagePromise: Promise<Page> | null = null;
   private _wkPage: WKPage | null = null;
+  private _provisionalPage: WKProvisionalPage | null = null;
   private readonly _firstTargetPromise: Promise<void>;
   private _firstTargetCallback?: () => void;
   private readonly _sessions = new Map<string, WKSession>();
@@ -79,7 +78,7 @@ export class WKPageProxy {
 
   private _isProvisionalCrossProcessLoadInProgress() : boolean {
     for (const anySession of this._sessions.values()) {
-      if ((anySession as any)[provisionalMessagesSymbol])
+      if ((anySession as any)[isPovisionalSymbol])
         return true;
     }
     return false;
@@ -113,7 +112,7 @@ export class WKPageProxy {
     await this._firstTargetPromise;
     let session: WKSession | undefined;
     for (const anySession of this._sessions.values()) {
-      if (!(anySession as any)[provisionalMessagesSymbol]) {
+      if (!(anySession as any)[isPovisionalSymbol]) {
         session = anySession;
         break;
       }
@@ -123,7 +122,7 @@ export class WKPageProxy {
     this._wkPage.setSession(session!);
     await Promise.all([
       this._wkPage._initializePageProxySession(),
-      this._wkPage._initializeSession(session!, false),
+      this._wkPage._initializeSession(session!),
     ]);
     return this._wkPage._page;
   }
@@ -144,9 +143,12 @@ export class WKPageProxy {
       this._firstTargetCallback = undefined;
     }
     if (targetInfo.isProvisional)
-      (session as any)[provisionalMessagesSymbol] = [];
-    if (targetInfo.isProvisional && this._wkPage)
-      this._wkPage._initializeSession(session, true);
+      (session as any)[isPovisionalSymbol] = true;
+    if (targetInfo.isProvisional && this._wkPage) {
+      assert(!this._provisionalPage);
+      this._provisionalPage = new WKProvisionalPage(session, this._wkPage);
+      this._wkPage._initializeSession(session);
+    }
     if (targetInfo.isPaused)
       this._pageProxySession.send('Target.resume', { targetId: targetInfo.targetId }).catch(debugError);
   }
@@ -157,6 +159,10 @@ export class WKPageProxy {
     if (session)
       session.dispose();
     this._sessions.delete(targetId);
+    if (this._provisionalPage && this._provisionalPage._session === session) {
+      this._provisionalPage.dispose();
+      this._provisionalPage = null;
+    }
     if (this._wkPage && this._wkPage._session === session && crashed)
       this._wkPage.didClose(crashed);
   }
@@ -165,11 +171,7 @@ export class WKPageProxy {
     const { targetId, message } = event;
     const session = this._sessions.get(targetId);
     assert(session, 'Unknown target: ' + targetId);
-    const provisionalMessages = (session as any)[provisionalMessagesSymbol];
-    if (provisionalMessages)
-      provisionalMessages.push(message);
-    else
-      session!.dispatchMessage(JSON.parse(message));
+    session!.dispatchMessage(JSON.parse(message));
   }
 
   private _onDidCommitProvisionalTarget(event: Protocol.Target.didCommitProvisionalTargetPayload) {
@@ -180,11 +182,12 @@ export class WKPageProxy {
     assert(oldSession, 'Unknown old target: ' + oldTargetId);
     // TODO: make some calls like screenshot catch swapped out error and retry.
     oldSession!.errorText = 'Target was swapped out.';
-    const provisionalMessages = (newSession as any)[provisionalMessagesSymbol];
-    assert(provisionalMessages, 'Committing target must be provisional');
-    (newSession as any)[provisionalMessagesSymbol] = undefined;
-    for (const message of provisionalMessages)
-      newSession!.dispatchMessage(JSON.parse(message));
-    this._wkPage!.setSession(newSession!);
+    (newSession as any)[isPovisionalSymbol] = undefined;
+    if (this._provisionalPage) {
+      this._provisionalPage.dispose();
+      this._provisionalPage = null;
+    }
+    if (this._wkPage)
+      this._wkPage.setSession(newSession!);
   }
 }
diff --git a/src/webkit/wkProvisionalPage.ts b/src/webkit/wkProvisionalPage.ts
new file mode 100644
index 0000000000..318216f293
--- /dev/null
+++ b/src/webkit/wkProvisionalPage.ts
@@ -0,0 +1,48 @@
+/**
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { WKSession } from './wkConnection';
+import { WKPage } from './wkPage';
+import { RegisteredListener, helper } from '../helper';
+
+export class WKProvisionalPage {
+  readonly _session: WKSession;
+  private readonly _wkPage: WKPage;
+  private _sessionListeners: RegisteredListener[] = [];
+
+  constructor(session: WKSession, page: WKPage) {
+    this._session = session;
+    this._wkPage = page;
+
+    this._sessionListeners = [
+      'Network.requestWillBeSent',
+      'Network.requestIntercepted',
+      'Network.responseReceived',
+      'Network.loadingFinished',
+      'Network.loadingFailed',
+    ].map(name => helper.addEventListener(this._session, name, args => this._onNetworkEvent(name, args)));
+  }
+  private _onNetworkEvent(eventName: string, payload: any) {
+    // Pretend that the events happened in the same process.
+    if (payload.frameId)
+      payload.frameId = this._wkPage._page._frameManager.mainFrame()._id;
+    this._wkPage._session.emit(eventName, payload);
+  }
+
+  dispose() {
+    helper.removeEventListeners(this._sessionListeners);
+  }
+}
\ No newline at end of file