File Extension in robots.txt when using mod_rewrite

When I use mod_rewrite in my .htaccess to rewrite all example.com/page.php to example.com/page, and I want to disallow certain pages in the robots.txt, do I write Disallow: /page.php or Disallow: /page? If it's the latter, I'd also use Allow: /$ to refer to the index.php, right?