diff --git a/examples/detect-sniff.js b/examples/detect-sniff.js
index 656387d7..b6727ecf 100644
--- a/examples/detect-sniff.js
+++ b/examples/detect-sniff.js
@@ -17,8 +17,8 @@
 const puppeteer = require('puppeteer');
 
 function sniffDetector() {
-  let userAgent = window.navigator.userAgent;
-  let platform = window.navigator.platform;
+  const userAgent = window.navigator.userAgent;
+  const platform = window.navigator.platform;
 
   window.navigator.__defineGetter__('userAgent', function() {
     window.navigator.sniffed = true;
diff --git a/examples/screenshot-fullpage.js b/examples/screenshot-fullpage.js
index ae06657a..de74d891 100644
--- a/examples/screenshot-fullpage.js
+++ b/examples/screenshot-fullpage.js
@@ -20,7 +20,7 @@ const devices = require('puppeteer/DeviceDescriptors');
 (async() => {
 
 const browser = await puppeteer.launch();
-let page = await browser.newPage();
+const page = await browser.newPage();
 await page.emulate(devices['iPhone 6']);
 await page.goto('https://www.nytimes.com/');
 await page.screenshot({path: 'full.png', fullPage: true});