I am getting pages loading with a 500 internal server error, due I believe to a directive that Apache has not been configured to allow.

I have AllowOverride set to all, and a .htaccess file, including:

<FilesMatch "\.(eot|ico|pdf|flv|jpg|jpeg|png|gif|svg|swf|ttf|woff)$">
Header set Cache-Control "max-age=31536000, public"
Header set Expires "Wed, 23 Apr 2014 17:00:01 UTC"

/var/log/apache2/error.log has:

[Sat Jul 20 15:12:36 2013] [alert] [client] /home/jonathan/.htaccess: Invalid command 'Header', perhaps misspelled or defined by a module not included in the server configuration

What do I need to specify so that Apache2 will properly handle the 'Header' directive?

2 Answers 2


With apache2, just run a2enmod headers and then sudo service apache2 restart and it will install the headers module automatically.

  • 3
    This answer should be accepted Commented Dec 9, 2015 at 15:37
  • 2
    Indeed this answer is the best, however I dare to say that some modern GNU/Linux distros (like the latest Debian) are based on systemd and have a different syntax on managing services. Restart Apache: sudo systemctl restart apache2.service. However, as of now a fallback function exists and thus the old sudo service command does work. But it may stop working in the nearest future. Commented Jan 12, 2016 at 19:24
  • a2enmod is in /usr/sbin on my system. That's not in my non-sudoer user's PATH, so a2enmod isn't discoverable unless you're root. TL;DR: run sudo a2enmod instead of just a2enmod. Commented Jan 9, 2019 at 21:50

You'll need to add a line like:

LoadModule headers_module modules/mod_headers.so

To your httpd.conf to add support for that. In Ubuntu and similar, you can do a2enmod headers and it'll automatically enable it in your configuration.

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