diff --git a/lib/BrowserFetcher.js b/lib/BrowserFetcher.js
index c5136a0e186c5..4433df9fe75ea 100644
--- a/lib/BrowserFetcher.js
+++ b/lib/BrowserFetcher.js
@@ -125,7 +125,7 @@ class BrowserFetcher {
 
   /**
    * @param {string} revision
-   * @param {?function(number, number)} progressCallback
+   * @param {?function(number, number):void} progressCallback
    * @return {!Promise<!BrowserFetcher.RevisionInfo>}
    */
   async download(revision, progressCallback) {
@@ -217,7 +217,7 @@ function parseFolderPath(folderPath) {
 /**
  * @param {string} url
  * @param {string} destinationPath
- * @param {?function(number, number)} progressCallback
+ * @param {?function(number, number):void} progressCallback
  * @return {!Promise}
  */
 function downloadFile(url, destinationPath, progressCallback) {
diff --git a/lib/FrameManager.js b/lib/FrameManager.js
index 26e5179f9c314..d2e805f2826e3 100644
--- a/lib/FrameManager.js
+++ b/lib/FrameManager.js
@@ -428,7 +428,7 @@ class Frame {
   }
 
   /**
-   * @param {function()|string} pageFunction
+   * @param {Function|string} pageFunction
    * @param {!Array<*>} args
    * @return {!Promise<!Puppeteer.JSHandle>}
    */
diff --git a/lib/Page.js b/lib/Page.js
index 01ceff67d2bc6..62b9064d0b9e4 100644
--- a/lib/Page.js
+++ b/lib/Page.js
@@ -292,7 +292,7 @@ class Page extends EventEmitter {
   }
 
   /**
-   * @param {function()|string} pageFunction
+   * @param {Function|string} pageFunction
    * @param {!Array<*>} args
    * @return {!Promise<!Puppeteer.JSHandle>}
    */
@@ -312,7 +312,7 @@ class Page extends EventEmitter {
 
   /**
    * @param {string} selector
-   * @param {function()|string} pageFunction
+   * @param {Function|string} pageFunction
    * @param {!Array<*>} args
    * @return {!Promise<(!Object|undefined)>}
    */
@@ -412,7 +412,7 @@ class Page extends EventEmitter {
 
   /**
    * @param {string} name
-   * @param {function(?)} puppeteerFunction
+   * @param {Function} puppeteerFunction
    */
   async exposeFunction(name, puppeteerFunction) {
     if (this._pageBindings.has(name))
@@ -782,7 +782,7 @@ class Page extends EventEmitter {
   }
 
   /**
-   * @param {function()|string} pageFunction
+   * @param {Function|string} pageFunction
    * @param {!Array<*>} args
    * @return {!Promise<*>}
    */
@@ -791,7 +791,7 @@ class Page extends EventEmitter {
   }
 
   /**
-   * @param {function()|string} pageFunction
+   * @param {Function|string} pageFunction
    * @param {!Array<*>} args
    */
   async evaluateOnNewDocument(pageFunction, ...args) {
@@ -1054,7 +1054,7 @@ class Page extends EventEmitter {
   }
 
   /**
-   * @param {function()} pageFunction
+   * @param {Function} pageFunction
    * @param {!{polling?: string|number, timeout?: number}=} options
    * @param {!Array<*>} args
    * @return {!Promise<!Puppeteer.JSHandle>}
diff --git a/lib/TaskQueue.js b/lib/TaskQueue.js
index b3facc286cf3c..8cfb7a726e1eb 100644
--- a/lib/TaskQueue.js
+++ b/lib/TaskQueue.js
@@ -4,7 +4,7 @@ class TaskQueue {
   }
 
   /**
-   * @param {function()} task
+   * @param {Function} task
    * @return {!Promise}
    */
   postTask(task) {
diff --git a/lib/Worker.js b/lib/Worker.js
index f3d8928d5d617..5ac00617aa97c 100644
--- a/lib/Worker.js
+++ b/lib/Worker.js
@@ -21,8 +21,8 @@ class Worker extends EventEmitter {
   /**
    * @param {Puppeteer.CDPSession} client
    * @param {string} url
-   * @param {function(!string, !Array<!JSHandle>, Protocol.Runtime.StackTrace=)} consoleAPICalled
-   * @param {function(!Protocol.Runtime.ExceptionDetails)} exceptionThrown
+   * @param {function(string, !Array<!JSHandle>, Protocol.Runtime.StackTrace=):void} consoleAPICalled
+   * @param {function(!Protocol.Runtime.ExceptionDetails):void} exceptionThrown
    */
   constructor(client, url, consoleAPICalled, exceptionThrown) {
     super();
@@ -58,7 +58,7 @@ class Worker extends EventEmitter {
   }
 
   /**
-   * @param {function()|string} pageFunction
+   * @param {Function|string} pageFunction
    * @param {!Array<*>} args
    * @return {!Promise<*>}
    */
@@ -67,7 +67,7 @@ class Worker extends EventEmitter {
   }
 
   /**
-   * @param {function()|string} pageFunction
+   * @param {Function|string} pageFunction
    * @param {!Array<*>} args
    * @return {!Promise<!JSHandle>}
    */
diff --git a/lib/helper.js b/lib/helper.js
index 169a8218c9a09..cb8d1ff4a71ad 100644
--- a/lib/helper.js
+++ b/lib/helper.js
@@ -158,7 +158,7 @@ class Helper {
   /**
    * @param {!NodeJS.EventEmitter} emitter
    * @param {(string|symbol)} eventName
-   * @param {function(?)} handler
+   * @param {function(?):void} handler
    * @return {{emitter: !NodeJS.EventEmitter, eventName: (string|symbol), handler: function(?)}}
    */
   static addEventListener(emitter, eventName, handler) {
@@ -167,7 +167,7 @@ class Helper {
   }
 
   /**
-   * @param {!Array<{emitter: !NodeJS.EventEmitter, eventName: (string|symbol), handler: function(?)}>} listeners
+   * @param {!Array<{emitter: !NodeJS.EventEmitter, eventName: (string|symbol), handler: function(?):void}>} listeners
    */
   static removeEventListeners(listeners) {
     for (const listener of listeners)
diff --git a/package.json b/package.json
index fa2906ad7e8da..322a64b1c5e59 100644
--- a/package.json
+++ b/package.json
@@ -57,7 +57,7 @@
     "pixelmatch": "^4.0.2",
     "pngjs": "^3.3.3",
     "text-diff": "^1.0.1",
-    "typescript": "3.1.6"
+    "typescript": "3.2.2"
   },
   "browser": {
     "./lib/BrowserFetcher.js": false,