diff --git a/index.js b/index.js
index 133f05516a250..e7143fb3a5b18 100644
--- a/index.js
+++ b/index.js
@@ -21,6 +21,16 @@ try {
   asyncawait = false;
 }
 
+if (asyncawait) {
+  const {helper} = require('./lib/helper');
+  const api = require('./lib/api');
+  for (const className in api) {
+    // Puppeteer-web excludes certain classes from bundle, e.g. BrowserFetcher.
+    if (typeof api[className] === 'function')
+      helper.installAsyncStackHooks(api[className]);
+  }
+}
+
 // If node does not support async await, use the compiled version.
 const Puppeteer = asyncawait ? require('./lib/Puppeteer') : require('./node6/lib/Puppeteer');
 const packageJson = require('./package.json');
diff --git a/lib/Accessibility.js b/lib/Accessibility.js
index 3bb7deb4d0724..f65642bf51c66 100644
--- a/lib/Accessibility.js
+++ b/lib/Accessibility.js
@@ -13,7 +13,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-const {helper} = require('./helper');
 
 /**
  * @typedef {Object} SerializedAXNode
@@ -390,4 +389,3 @@ class AXNode {
 }
 
 module.exports = {Accessibility};
-helper.tracePublicAPI(Accessibility);
diff --git a/lib/Browser.js b/lib/Browser.js
index eaa1584a3adf3..8d2a5929060e4 100644
--- a/lib/Browser.js
+++ b/lib/Browser.js
@@ -373,7 +373,4 @@ class BrowserContext extends EventEmitter {
   }
 }
 
-helper.tracePublicAPI(BrowserContext);
-helper.tracePublicAPI(Browser);
-
 module.exports = {Browser, BrowserContext};
diff --git a/lib/Connection.js b/lib/Connection.js
index 616974a65af84..bd9be3d49d3c5 100644
--- a/lib/Connection.js
+++ b/lib/Connection.js
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-const {helper, assert} = require('./helper');
+const {assert} = require('./helper');
 const {Events} = require('./Events');
 const debugProtocol = require('debug')('puppeteer:protocol');
 const EventEmitter = require('events');
@@ -216,8 +216,6 @@ class CDPSession extends EventEmitter {
   }
 }
 
-helper.tracePublicAPI(CDPSession);
-
 /**
  * @param {!Error} error
  * @param {string} method
diff --git a/lib/Coverage.js b/lib/Coverage.js
index f4e3d31f37534..5f88c10e9a157 100644
--- a/lib/Coverage.js
+++ b/lib/Coverage.js
@@ -64,7 +64,6 @@ class Coverage {
 }
 
 module.exports = {Coverage};
-helper.tracePublicAPI(Coverage);
 
 class JSCoverage {
   /**
diff --git a/lib/Dialog.js b/lib/Dialog.js
index 89e3092ca17f9..cbdc271916937 100644
--- a/lib/Dialog.js
+++ b/lib/Dialog.js
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-const {helper, assert} = require('./helper');
+const {assert} = require('./helper');
 
 class Dialog {
   /**
@@ -81,4 +81,3 @@ Dialog.Type = {
 };
 
 module.exports = {Dialog};
-helper.tracePublicAPI(Dialog);
diff --git a/lib/ExecutionContext.js b/lib/ExecutionContext.js
index b832039dd6606..c17a5de1e3271 100644
--- a/lib/ExecutionContext.js
+++ b/lib/ExecutionContext.js
@@ -175,6 +175,4 @@ class ExecutionContext {
   }
 }
 
-helper.tracePublicAPI(ExecutionContext);
-
 module.exports = {ExecutionContext, EVALUATION_SCRIPT_URL};
diff --git a/lib/FrameManager.js b/lib/FrameManager.js
index 1f5d967e8ed28..513dbf9ee171b 100644
--- a/lib/FrameManager.js
+++ b/lib/FrameManager.js
@@ -680,7 +680,6 @@ class Frame {
     this._parentFrame = null;
   }
 }
-helper.tracePublicAPI(Frame);
 
 function assertNoLegacyNavigationOptions(options) {
   assert(options['networkIdleTimeout'] === undefined, 'ERROR: networkIdleTimeout option is no longer supported.');
diff --git a/lib/Input.js b/lib/Input.js
index b4c02f95f8bcc..a0789b1e160af 100644
--- a/lib/Input.js
+++ b/lib/Input.js
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-const {helper, assert} = require('./helper');
+const {assert} = require('./helper');
 const keyDefinitions = require('./USKeyboardLayout');
 
 /**
@@ -302,6 +302,3 @@ class Touchscreen {
 }
 
 module.exports = { Keyboard, Mouse, Touchscreen};
-helper.tracePublicAPI(Keyboard);
-helper.tracePublicAPI(Mouse);
-helper.tracePublicAPI(Touchscreen);
diff --git a/lib/JSHandle.js b/lib/JSHandle.js
index 226b1ed06761e..2190a9d381a5d 100644
--- a/lib/JSHandle.js
+++ b/lib/JSHandle.js
@@ -122,8 +122,6 @@ class JSHandle {
   }
 }
 
-helper.tracePublicAPI(JSHandle);
-
 class ElementHandle extends JSHandle {
   /**
    * @param {!Puppeteer.ExecutionContext} context
@@ -507,5 +505,4 @@ function computeQuadArea(quad) {
  * @property {number} height
  */
 
-helper.tracePublicAPI(ElementHandle);
 module.exports = {createJSHandle, JSHandle, ElementHandle};
diff --git a/lib/NetworkManager.js b/lib/NetworkManager.js
index 3e63ce887ee60..79263cd9ca715 100644
--- a/lib/NetworkManager.js
+++ b/lib/NetworkManager.js
@@ -507,8 +507,6 @@ const errorReasons = {
   'failed': 'Failed',
 };
 
-helper.tracePublicAPI(Request);
-
 class Response {
   /**
    * @param {!Puppeteer.CDPSession} client
@@ -649,7 +647,6 @@ class Response {
     return this._request.frame();
   }
 }
-helper.tracePublicAPI(Response);
 
 const IGNORED_HEADERS = new Set(['accept', 'referer', 'x-devtools-emulate-network-conditions-client-id', 'cookie', 'origin', 'content-type', 'intervention']);
 
@@ -798,4 +795,4 @@ const statusTexts = {
   '511': 'Network Authentication Required',
 };
 
-module.exports = {Request, Response, NetworkManager};
+module.exports = {Request, Response, NetworkManager, SecurityDetails};
diff --git a/lib/Page.js b/lib/Page.js
index 1bd7334bc88b0..2e588efc04bf6 100644
--- a/lib/Page.js
+++ b/lib/Page.js
@@ -1270,5 +1270,4 @@ class ConsoleMessage {
 }
 
 
-module.exports = {Page};
-helper.tracePublicAPI(Page);
+module.exports = {Page, ConsoleMessage};
diff --git a/lib/Puppeteer.js b/lib/Puppeteer.js
index 314aff6f83925..cf69b027df54c 100644
--- a/lib/Puppeteer.js
+++ b/lib/Puppeteer.js
@@ -13,7 +13,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-const {helper} = require('./helper');
 const Launcher = require('./Launcher');
 const BrowserFetcher = require('./BrowserFetcher');
 
@@ -68,4 +67,3 @@ module.exports = class {
   }
 };
 
-helper.tracePublicAPI(module.exports, 'Puppeteer');
diff --git a/lib/Target.js b/lib/Target.js
index b42ffe90e450c..e1e4ae4a93832 100644
--- a/lib/Target.js
+++ b/lib/Target.js
@@ -1,6 +1,21 @@
+/**
+ * Copyright 2019 Google Inc. All rights reserved.
+ *
+ * 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.
+ */
+
 const {Events} = require('./Events');
 const {Page} = require('./Page');
-const {helper} = require('./helper');
 
 class Target {
   /**
@@ -113,6 +128,4 @@ class Target {
   }
 }
 
-helper.tracePublicAPI(Target);
-
 module.exports = {Target};
diff --git a/lib/Tracing.js b/lib/Tracing.js
index d8c8ac7f2bd05..37fc8410b6e59 100644
--- a/lib/Tracing.js
+++ b/lib/Tracing.js
@@ -101,6 +101,5 @@ class Tracing {
     }
   }
 }
-helper.tracePublicAPI(Tracing);
 
 module.exports = Tracing;
diff --git a/lib/Worker.js b/lib/Worker.js
index 1161e6b844fa1..766116523e56a 100644
--- a/lib/Worker.js
+++ b/lib/Worker.js
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 const EventEmitter = require('events');
-const {helper, debugError} = require('./helper');
+const {debugError} = require('./helper');
 const {ExecutionContext} = require('./ExecutionContext');
 const {JSHandle} = require('./JSHandle');
 
@@ -78,4 +78,3 @@ class Worker extends EventEmitter {
 }
 
 module.exports = {Worker};
-helper.tracePublicAPI(Worker);
diff --git a/lib/api.js b/lib/api.js
new file mode 100644
index 0000000000000..135a69eaf3ecc
--- /dev/null
+++ b/lib/api.js
@@ -0,0 +1,42 @@
+/**
+ * Copyright 2019 Google Inc. All rights reserved.
+ *
+ * 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.
+ */
+
+module.exports = {
+  Accessibility: require('./Accessibility').Accessibility,
+  Browser: require('./Browser').Browser,
+  BrowserContext: require('./Browser').BrowserContext,
+  BrowserFetcher: require('./BrowserFetcher'),
+  CDPSession: require('./Connection').CDPSession,
+  ConsoleMessage: require('./Page').ConsoleMessage,
+  Coverage: require('./Coverage').Coverage,
+  Dialog: require('./Dialog').Dialog,
+  ElementHandle: require('./JSHandle').ElementHandle,
+  ExecutionContext: require('./ExecutionContext').ExecutionContext,
+  Frame: require('./FrameManager').Frame,
+  JSHandle: require('./JSHandle').JSHandle,
+  Keyboard: require('./Input').Keyboard,
+  Mouse: require('./Input').Mouse,
+  Page: require('./Page').Page,
+  Puppeteer: require('./Puppeteer'),
+  Request: require('./NetworkManager').Request,
+  Response: require('./NetworkManager').Response,
+  SecurityDetails: require('./NetworkManager').SecurityDetails,
+  Target: require('./Target').Target,
+  TimeoutError: require('./Errors').TimeoutError,
+  Touchscreen: require('./Input').Touchscreen,
+  Tracing: require('./Tracing'),
+  Worker: require('./Worker').Worker,
+};
diff --git a/lib/helper.js b/lib/helper.js
index 0bc94199a6e66..ee1055c70a4a0 100644
--- a/lib/helper.js
+++ b/lib/helper.js
@@ -16,41 +16,6 @@
 const {TimeoutError} = require('./Errors');
 
 const debugError = require('debug')(`puppeteer:error`);
-/** @type {?Map<string, boolean>} */
-let apiCoverage = null;
-
-/**
- * @param {!Object} classType
- * @param {string=} publicName
- */
-function traceAPICoverage(classType, publicName) {
-  if (!apiCoverage)
-    return;
-
-  let className = publicName || classType.prototype.constructor.name;
-  className = className.substring(0, 1).toLowerCase() + className.substring(1);
-  for (const methodName of Reflect.ownKeys(classType.prototype)) {
-    const method = Reflect.get(classType.prototype, methodName);
-    if (methodName === 'constructor' || typeof methodName !== 'string' || methodName.startsWith('_') || typeof method !== 'function')
-      continue;
-    apiCoverage.set(`${className}.${methodName}`, false);
-    Reflect.set(classType.prototype, methodName, function(...args) {
-      apiCoverage.set(`${className}.${methodName}`, true);
-      return method.call(this, ...args);
-    });
-  }
-
-  if (classType.Events) {
-    for (const event of Object.values(classType.Events))
-      apiCoverage.set(`${className}.emit(${JSON.stringify(event)})`, false);
-    const method = Reflect.get(classType.prototype, 'emit');
-    Reflect.set(classType.prototype, 'emit', function(event, ...args) {
-      if (this.listenerCount(event))
-        apiCoverage.set(`${className}.emit(${JSON.stringify(event)})`, true);
-      return method.call(this, event, ...args);
-    });
-  }
-}
 
 class Helper {
   /**
@@ -133,9 +98,8 @@ class Helper {
 
   /**
    * @param {!Object} classType
-   * @param {string=} publicName
    */
-  static tracePublicAPI(classType, publicName) {
+  static installAsyncStackHooks(classType) {
     for (const methodName of Reflect.ownKeys(classType.prototype)) {
       const method = Reflect.get(classType.prototype, methodName);
       if (methodName === 'constructor' || typeof methodName !== 'string' || methodName.startsWith('_') || typeof method !== 'function' || method.constructor.name !== 'AsyncFunction')
@@ -151,8 +115,6 @@ class Helper {
         });
       });
     }
-
-    traceAPICoverage(classType, publicName);
   }
 
   /**
@@ -175,17 +137,6 @@ class Helper {
     listeners.splice(0, listeners.length);
   }
 
-  /**
-   * @return {?Map<string, boolean>}
-   */
-  static publicAPICoverage() {
-    return apiCoverage;
-  }
-
-  static recordPublicAPICoverage() {
-    apiCoverage = new Map();
-  }
-
   /**
    * @param {!Object} obj
    * @return {boolean}
diff --git a/test/test.js b/test/test.js
index 392cfec11f663..10b1a6a8a65d0 100644
--- a/test/test.js
+++ b/test/test.js
@@ -75,32 +75,24 @@ beforeEach(async({server, httpsServer}) => {
   httpsServer.reset();
 });
 
-describe('Chromium', () => {
-  const {helper} = require('../lib/helper');
-  if (process.env.COVERAGE)
-    helper.recordPublicAPICoverage();
+const CHROMIUM_NO_COVERAGE = new Set([
+  'page.bringToFront',
+  'securityDetails.subjectName',
+  'securityDetails.issuer',
+  'securityDetails.validFrom',
+  'securityDetails.validTo',
+  ...(headless ? [] : ['page.pdf']),
+]);
 
+describe('Chromium', () => {
   require('./puppeteer.spec.js').addTests({
     product: 'Chromium',
     puppeteer: utils.requireRoot('index'),
     defaultBrowserOptions,
     testRunner,
   });
-  if (process.env.COVERAGE) {
-    describe('COVERAGE', function() {
-      const coverage = helper.publicAPICoverage();
-      const disabled = new Set(['page.bringToFront']);
-      if (!headless)
-        disabled.add('page.pdf');
-
-      for (const method of coverage.keys()) {
-        (disabled.has(method) ? xit : it)(`public api '${method}' should be called`, async({page, server}) => {
-          if (!coverage.get(method))
-            throw new Error('NOT CALLED!');
-        });
-      }
-    });
-  }
+  if (process.env.COVERAGE)
+    utils.recordAPICoverage(testRunner, require('../lib/api'), CHROMIUM_NO_COVERAGE);
 });
 
 if (process.env.CI && testRunner.hasFocusedTestsOrSuites()) {
diff --git a/test/utils.js b/test/utils.js
index 05e1c98220f75..debe12cdd2b97 100644
--- a/test/utils.js
+++ b/test/utils.js
@@ -18,7 +18,51 @@ const fs = require('fs');
 const path = require('path');
 const PROJECT_ROOT = fs.existsSync(path.join(__dirname, '..', 'package.json')) ? path.join(__dirname, '..') : path.join(__dirname, '..', '..');
 
+/**
+ * @param {Map<string, boolean>} apiCoverage
+ * @param {string} className
+ * @param {!Object} classType
+ */
+function traceAPICoverage(apiCoverage, className, classType) {
+  className = className.substring(0, 1).toLowerCase() + className.substring(1);
+  for (const methodName of Reflect.ownKeys(classType.prototype)) {
+    const method = Reflect.get(classType.prototype, methodName);
+    if (methodName === 'constructor' || typeof methodName !== 'string' || methodName.startsWith('_') || typeof method !== 'function')
+      continue;
+    apiCoverage.set(`${className}.${methodName}`, false);
+    Reflect.set(classType.prototype, methodName, function(...args) {
+      apiCoverage.set(`${className}.${methodName}`, true);
+      return method.call(this, ...args);
+    });
+  }
+
+  if (classType.Events) {
+    for (const event of Object.values(classType.Events))
+      apiCoverage.set(`${className}.emit(${JSON.stringify(event)})`, false);
+    const method = Reflect.get(classType.prototype, 'emit');
+    Reflect.set(classType.prototype, 'emit', function(event, ...args) {
+      if (this.listenerCount(event))
+        apiCoverage.set(`${className}.emit(${JSON.stringify(event)})`, true);
+      return method.call(this, event, ...args);
+    });
+  }
+}
+
 const utils = module.exports = {
+  recordAPICoverage: function(testRunner, api, disabled) {
+    const coverage = new Map();
+    for (const [className, classType] of Object.entries(api))
+      traceAPICoverage(coverage, className, classType);
+    testRunner.describe('COVERAGE', () => {
+      for (const method of coverage.keys()) {
+        (disabled.has(method) ? testRunner.xit : testRunner.it)(`public api '${method}' should be called`, async({page, server}) => {
+          if (!coverage.get(method))
+            throw new Error('NOT CALLED!');
+        });
+      }
+    });
+  },
+
   /**
    * @return {string}
    */
diff --git a/utils/doclint/check_public_api/index.js b/utils/doclint/check_public_api/index.js
index 0deb9019d2384..94861aae8b313 100644
--- a/utils/doclint/check_public_api/index.js
+++ b/utils/doclint/check_public_api/index.js
@@ -19,26 +19,6 @@ const mdBuilder = require('./MDBuilder');
 const Documentation = require('./Documentation');
 const Message = require('../Message');
 
-const EXCLUDE_CLASSES = new Set([
-  'AXNode',
-  'CSSCoverage',
-  'Connection',
-  'CustomError',
-  'DOMWorld',
-  'EmulationManager',
-  'FrameManager',
-  'JSCoverage',
-  'Helper',
-  'Launcher',
-  'Multimap',
-  'LifecycleWatcher',
-  'NetworkManager',
-  'PipeTransport',
-  'TaskQueue',
-  'WaitTask',
-  'WebSocketTransport',
-]);
-
 const EXCLUDE_PROPERTIES = new Set([
   'Browser.create',
   'Headers.fromPayload',
@@ -55,7 +35,7 @@ const EXCLUDE_PROPERTIES = new Set([
 module.exports = async function lint(page, mdSources, jsSources) {
   const mdResult = await mdBuilder(page, mdSources);
   const jsResult = await jsBuilder(jsSources);
-  const jsDocumentation = filterJSDocumentation(jsResult.documentation);
+  const jsDocumentation = filterJSDocumentation(jsSources, jsResult.documentation);
   const mdDocumentation = mdResult.documentation;
 
   const jsErrors = jsResult.errors;
@@ -126,14 +106,19 @@ function checkSorting(doc) {
 }
 
 /**
+ * @param {!Array<!Source>} jsSources
  * @param {!Documentation} jsDocumentation
  * @return {!Documentation}
  */
-function filterJSDocumentation(jsDocumentation) {
-  // Filter classes and methods.
+function filterJSDocumentation(jsSources, jsDocumentation) {
+  const apijs = jsSources.find(source => source.name() === 'api.js');
+  let includedClasses = null;
+  if (apijs)
+    includedClasses = new Set(Object.keys(require(apijs.filePath())));
+  // Filter private classes and methods.
   const classes = [];
   for (const cls of jsDocumentation.classesArray) {
-    if (EXCLUDE_CLASSES.has(cls.name))
+    if (includedClasses && !includedClasses.has(cls.name))
       continue;
     const members = cls.membersArray.filter(member => !EXCLUDE_PROPERTIES.has(`${cls.name}.${member.name}`));
     classes.push(new Documentation.Class(cls.name, members));