title: PHP: Use of undefined constant ENT_HTML5 - assumed 'ENT_HTML5'
body: <p>I'm getting the error:</p>
  
  <pre><code>Use of undefined constant ENT_HTML5 - assumed 'ENT_HTML5' in /blahblahpath/application/models/Post.php on line 12
  </code></pre>
  
  <p>in a simple model that deals with some <code>POST</code> input in a forum app. The line that triggers this is as such:</p>
  
  <pre><code>$this-&gt;set_attribute('body', htmlspecialchars(strip_tags($body), ENT_NOQUOTES | ENT_HTML5));
  </code></pre>
  
  <p>Very simple.. I'm wondering if this is a server error because I just migrated to a new server and only encounter the problem there. No idea where to start and Googling hasn't yielded much. Using Ubuntu Server 12.04 LTS (the Windows Azure version) and PHP 5.3.10-1ubuntu3.10. </p>