diff --git a/residential/samples/puppeteer.mdx b/residential/samples/puppeteer.mdx
index b3b1cfd..2f0436c 100644
--- a/residential/samples/puppeteer.mdx
+++ b/residential/samples/puppeteer.mdx
@@ -14,11 +14,11 @@ const puppeteer = require('puppeteer');
   const page    = (await browser.pages())[0];
 
   await page.authenticate({
-    username: '{PROXY_USERNAME},
+    username: '{PROXY_USERNAME}',
     password: '{API_KEY}'
   });
   await page.goto('https://cloudflare.com/cdn-cgi/trace'); // Insert your target URL here
   console.log(await page.content());
   browser.close();
 })();
-```
\ No newline at end of file
+```