After moving my Drupal site to a new host, I got the following error in the error logs.

[error] 8707#0: *1 FastCGI sent in stderr: "PHP message: PHP Notice: Constant DATE_RFC7231 already defined in /ext/vhosts/public/includes/bootstrap.inc on line 258

How can I fix it?

My site currently says "The website encountered an unexpected error. Please try again later"

My setup is as follows:

  • Debian 8
  • PHP 7.0.21
  • MySQL 5.6
  • Drupal 7.54

2 Answers 2


Are you certain you're running PHP 5 and not a version of PHP 7? I've only ever seen that error when running PHP 7, and it was due to DATE_RFC7231 already defined in PHP 7.0.19 and 7.1.5.

Either way, the patches in that issue were committed and released with 7.55, so it might be worth trying a core update before anything else.

  • I've just tried to update site to Drupl 7.55. I ran draush cc all, and refreshe the site, stil the same error. Aug 3, 2017 at 13:13
  • I was also getting this with PHP 7 on a VM on Drupal 7. Downgraded to PHP 5, it went away. This was just this week, too.
    – Kevin
    Aug 3, 2017 at 13:14
  • @Chapabu, actually Drupal 7.55 did fix the error for me. Thanks for the help Aug 3, 2017 at 14:06

I solved following this tutorial:

Open /includes/bootstrap.inc
Go to line number 258
Comment out the following line:

//define(‘DATE_RFC7231’, ‘D, d M Y H:i:s \G\M\T’);

Then add following line:

if (!defined(‘DATE_RFC7231’)) {
define(‘DATE_RFC7231’, ‘D, d M Y H:i:s \G\M\T’);
  • 1
    There is not need to edit a Drupal core file: It's enough to update to any Drupal 7 version that is higher than 7.54.
    – apaderno
    Sep 16, 2021 at 10:35

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