diff --git a/lib/Connection.js b/lib/Connection.js
index cbda4e785a0..c99584c3046 100644
--- a/lib/Connection.js
+++ b/lib/Connection.js
@@ -117,9 +117,6 @@ class Connection extends EventEmitter {
     this._sessions.clear();
   }
 
-  /**
-   * @return {!Promise}
-   */
   dispose() {
     this._onClose();
     this._ws.close();
@@ -203,9 +200,6 @@ class Session extends EventEmitter {
     }
   }
 
-  /**
-   * @return {!Promise}
-   */
   async dispose() {
     await this._connection.send('Target.closeTarget', {targetId: this._targetId});
   }
diff --git a/lib/Dialog.js b/lib/Dialog.js
index dff77c73735..5e618878e95 100644
--- a/lib/Dialog.js
+++ b/lib/Dialog.js
@@ -47,7 +47,6 @@ class Dialog {
 
   /**
    * @param {string=} promptText
-   * @return {!Promise}
    */
   async accept(promptText) {
     console.assert(!this._handled, 'Cannot accept dialog which is already handled!');
@@ -58,9 +57,6 @@ class Dialog {
     });
   }
 
-  /**
-   * @return {!Promise}
-   */
   async dismiss() {
     console.assert(!this._handled, 'Cannot dismiss dialog which is already handled!');
     this._handled = true;
diff --git a/lib/ElementHandle.js b/lib/ElementHandle.js
index 1e8578b2225..697e4a40015 100644
--- a/lib/ElementHandle.js
+++ b/lib/ElementHandle.js
@@ -29,9 +29,6 @@ class ElementHandle {
     this._disposed = false;
   }
 
-  /**
-   * @return {!Promise}
-   */
   async dispose() {
     if (this._disposed)
       return;
@@ -77,9 +74,6 @@ class ElementHandle {
     return center;
   }
 
-  /**
-   * @return {!Promise}
-   */
   async hover() {
     const {x, y} = await this._visibleCenter();
     await this._mouse.move(x, y);
@@ -87,7 +81,6 @@ class ElementHandle {
 
   /**
    * @param {!Object=} options
-   * @return {!Promise}
    */
   async click(options) {
     const {x, y} = await this._visibleCenter();
diff --git a/lib/FrameManager.js b/lib/FrameManager.js
index c998122b5fc..5e632b038c6 100644
--- a/lib/FrameManager.js
+++ b/lib/FrameManager.js
@@ -284,7 +284,7 @@ class Frame {
 
   /**
    * @param {string} filePath
-   * @return {!Promise}
+   * @return {!Promise<*>}
    */
   async injectFile(filePath) {
     let contents = await new Promise((resolve, reject) => {
@@ -299,7 +299,6 @@ class Frame {
 
   /**
    * @param {string} url
-   * @return {!Promise}
    */
   async addScriptTag(url) {
     return this.evaluate(addScriptTag, url);
diff --git a/lib/Input.js b/lib/Input.js
index 623eed38a3d..8e93e47874c 100644
--- a/lib/Input.js
+++ b/lib/Input.js
@@ -29,7 +29,6 @@ class Keyboard {
   /**
    * @param {string} key
    * @param {{text: (string|undefined)}} options
-   * @return {!Promise}
    */
   async down(key, options = {}) {
     const text = options.text;
@@ -65,7 +64,6 @@ class Keyboard {
 
   /**
    * @param {string} key
-   * @return {!Promise}
    */
   async up(key) {
     this._modifiers &= ~this._modifierBit(key);
@@ -80,7 +78,6 @@ class Keyboard {
 
   /**
    * @param {string} char
-   * @return {!Promise}
    */
   async sendCharacter(char) {
     await this._client.send('Input.dispatchKeyEvent', {
diff --git a/lib/NetworkManager.js b/lib/NetworkManager.js
index 8ba24cbaf06..bb03ce15347 100644
--- a/lib/NetworkManager.js
+++ b/lib/NetworkManager.js
@@ -47,7 +47,6 @@ class NetworkManager extends EventEmitter {
 
   /**
    * @param {!Object<string, string>} extraHTTPHeaders
-   * @return {!Promise}
    */
   async setExtraHTTPHeaders(extraHTTPHeaders) {
     this._extraHTTPHeaders = {};
@@ -65,7 +64,6 @@ class NetworkManager extends EventEmitter {
 
   /**
    * @param {string} userAgent
-   * @return {!Promise}
    */
   async setUserAgent(userAgent) {
     return this._client.send('Network.setUserAgentOverride', { userAgent });
@@ -73,7 +71,6 @@ class NetworkManager extends EventEmitter {
 
   /**
    * @param {boolean} value
-   * @return {!Promise}
    */
   async setRequestInterceptionEnabled(value) {
     await this._client.send('Network.setRequestInterceptionEnabled', {enabled: !!value});
diff --git a/lib/Page.js b/lib/Page.js
index 6af1a427cec..90e75373922 100644
--- a/lib/Page.js
+++ b/lib/Page.js
@@ -205,7 +205,6 @@ class Page extends EventEmitter {
 
   /**
    * @param {string} url
-   * @return {!Promise}
    */
   async addScriptTag(url) {
     return this.mainFrame().addScriptTag(url);
@@ -213,7 +212,6 @@ class Page extends EventEmitter {
 
   /**
    * @param {string} filePath
-   * @return {!Promise}
    */
   async injectFile(filePath) {
     return this.mainFrame().injectFile(filePath);
@@ -252,7 +250,6 @@ class Page extends EventEmitter {
 
   /**
    * @param {!Object<string, string>} headers
-   * @return {!Promise}
    */
   async setExtraHTTPHeaders(headers) {
     return this._networkManager.setExtraHTTPHeaders(headers);
@@ -260,7 +257,6 @@ class Page extends EventEmitter {
 
   /**
    * @param {string} userAgent
-   * @return {!Promise}
    */
   async setUserAgent(userAgent) {
     return this._networkManager.setUserAgent(userAgent);
@@ -333,7 +329,6 @@ class Page extends EventEmitter {
 
   /**
    * @param {string} html
-   * @return {!Promise}
    */
   async setContent(html) {
     await this.evaluate(html => {
@@ -425,7 +420,6 @@ class Page extends EventEmitter {
 
   /**
    * @param {!Object} options
-   * @return {!Promise}
    */
   async emulate(options) {
     return Promise.all([
@@ -443,7 +437,6 @@ class Page extends EventEmitter {
 
   /**
    * @param {?string} mediaType
-   * @return {!Promise}
    */
   async emulateMedia(mediaType) {
     console.assert(mediaType === 'screen' || mediaType === 'print' || mediaType === null, 'Unsupported media type: ' + mediaType);
@@ -452,7 +445,6 @@ class Page extends EventEmitter {
 
   /**
    * @param {!Page.Viewport} viewport
-   * @return {!Promise}
    */
   async setViewport(viewport) {
     const needsReload = await this._emulationManager.emulateViewport(this._client, viewport);
@@ -480,7 +472,6 @@ class Page extends EventEmitter {
   /**
    * @param {function()|string} pageFunction
    * @param {!Array<*>} args
-   * @return {!Promise}
    */
   async evaluateOnNewDocument(pageFunction, ...args) {
     const source = helper.evaluationString(pageFunction, ...args);
@@ -627,9 +618,6 @@ class Page extends EventEmitter {
     return this.mainFrame().title();
   }
 
-  /**
-   * @return {!Promise}
-   */
   async close() {
     await this._client.dispose();
   }
@@ -644,7 +632,6 @@ class Page extends EventEmitter {
   /**
    * @param {string} selector
    * @param {!Object} options
-   * @return {!Promise}
    */
   async click(selector, options) {
     const handle = await this.$(selector);
@@ -655,7 +642,6 @@ class Page extends EventEmitter {
 
   /**
    * @param {string} selector
-   * @param {!Promise}
    */
   async hover(selector) {
     const handle = await this.$(selector);
@@ -666,7 +652,6 @@ class Page extends EventEmitter {
 
   /**
    * @param {string} selector
-   * @return {!Promise}
    */
   async focus(selector) {
     const handle = await this.$(selector);
@@ -678,7 +663,6 @@ class Page extends EventEmitter {
   /**
    * @param {string} text
    * @param {{delay: (number|undefined)}=} options
-   * @return {!Promise}
    */
   async type(text, options) {
     let delay = 0;
@@ -696,7 +680,6 @@ class Page extends EventEmitter {
   /**
    * @param {string} text
    * @param {!Object=} options
-   * @return {!Promise}
    */
   async press(key, options) {
     this._keyboard.down(key, options);
diff --git a/lib/Tracing.js b/lib/Tracing.js
index aadb7ad5662..c1975d42893 100644
--- a/lib/Tracing.js
+++ b/lib/Tracing.js
@@ -28,7 +28,6 @@ class Tracing {
 
   /**
    * @param {!Object} options
-   * @return {!Promise}
    */
   async start(options) {
     console.assert(!this._recording, 'Cannot start recording trace while already recording trace.');
@@ -52,9 +51,6 @@ class Tracing {
     });
   }
 
-  /**
-   * @return {!Promise}
-   */
   async stop() {
     let fulfill;
     const contentPromise = new Promise(x => fulfill = x);
@@ -69,7 +65,6 @@ class Tracing {
   /**
    * @param {string} handle
    * @param {string} path
-   * @return {!Promise}
    */
   async _readStream(handle, path) {
     let eof = false;
diff --git a/lib/helper.js b/lib/helper.js
index eefa5b8f1c2..5239d2ddc13 100644
--- a/lib/helper.js
+++ b/lib/helper.js
@@ -90,7 +90,6 @@ class Helper {
   /**
    * @param {!Session} client
    * @param {!Object} remoteObject
-   * @return {!Promise}
    */
   static async releaseObject(client, remoteObject) {
     if (!remoteObject.objectId)
diff --git a/test/frame-utils.js b/test/frame-utils.js
index ac59f2a8283..2de76772199 100644
--- a/test/frame-utils.js
+++ b/test/frame-utils.js
@@ -19,7 +19,6 @@ const utils = module.exports = {
    * @param {!Page} page
    * @param {string} frameId
    * @param {string} url
-   * @return {!Promise}
    */
   attachFrame: async function(page, frameId, url) {
     await page.evaluate(attachFrame, frameId, url);
@@ -36,7 +35,6 @@ const utils = module.exports = {
   /**
    * @param {!Page} page
    * @param {string} frameId
-   * @return {!Promise}
    */
   detachFrame: async function(page, frameId) {
     await page.evaluate(detachFrame, frameId);
@@ -51,7 +49,6 @@ const utils = module.exports = {
    * @param {!Page} page
    * @param {string} frameId
    * @param {string} url
-   * @return {!Promise}
    */
   navigateFrame: async function(page, frameId, url) {
     await page.evaluate(navigateFrame, frameId, url);
diff --git a/test/server/SimpleServer.js b/test/server/SimpleServer.js
index 411dd3a6613..583d32c289a 100644
--- a/test/server/SimpleServer.js
+++ b/test/server/SimpleServer.js
@@ -88,9 +88,6 @@ class SimpleServer {
     socket.once('close', () => this._sockets.delete(socket));
   }
 
-  /**
-   * @return {!Promise}
-   */
   async stop() {
     this.reset();
     for (const socket of this._sockets)
diff --git a/utils/check_availability.js b/utils/check_availability.js
index 14e99ea21c7..62350760ae6 100755
--- a/utils/check_availability.js
+++ b/utils/check_availability.js
@@ -63,9 +63,6 @@ const fromRevision = parseInt(process.argv[2], 10);
 const toRevision = parseInt(process.argv[3], 10);
 checkRangeAvailability(fromRevision, toRevision);
 
-/**
- * @return {!Promise}
- */
 async function checkOmahaProxyAvailability() {
   console.log('Fetching revisions from ' + OMAHA_PROXY);
   const platforms = await loadJSON(OMAHA_PROXY);
@@ -93,7 +90,6 @@ async function checkOmahaProxyAvailability() {
 /**
  * @param {number} fromRevision
  * @param {number} toRevision
- * @return {!Promise}
  */
 async function checkRangeAvailability(fromRevision, toRevision) {
   const table = new Table([10, 7, 7, 7, 7]);
@@ -107,7 +103,6 @@ async function checkRangeAvailability(fromRevision, toRevision) {
  * @param {!Table} table
  * @param {string} name
  * @param {number} revision
- * @return {!Promise}
  */
 async function checkAndDrawRevisionAvailability(table, name, revision) {
   const promises = [];