We are running CentOS 6 and PHP 5.3.8 (being an apache module) that ought to have JSON included in it's core (I am told). Searching at # php -i around the command line I can tell under Configure Command '--enable-json=shared' ... great!

However, searching at php_info() on the web site Configure Command shows '--disable-json'.

Not a problem I figured, I'll just do the installation using pecl:

# yum update php
# yum install php-pear
# yum install gcc
# pecl install json
# service httpd restart

Success, that aught to get it done I figured. However php -m shows:

PHP Warning: PHP Startup: Not able to load dynamic library '/usr/lib64/php/modules/json.so' - /usr/lib64/php/modules/json.so: undefined symbol: ZVAL_DELREF in Unknown online

Apologies if this sounds like an exotic question but does anybody know what's happening here and may you point me within the right direction regarding how to fix this to ensure that JSON begins working?

Thank you

Thought I'd follow-up using the solution. The PECL installation appeared to conflict with PHP 5.3.8 so after a little of research plus some advice I considered the thought of:

# yum remove php
# yum install php

However, after further advice rather opted for:

# yumdownloader php-common
# rpm -Uvh --force php-common*.rpm
# service httpd reload
# rm php-common*.rpm

This have been effective and JSON has become working again. Hope this can help another person.


  1. Login to SSH
  2. Make tmp and var/tmp professional

    mount -v -o remount,exec /tmp
    mount -v -o remount,exec /var/tmp

  3. No proceed and install JSON

    pecl install json

  4. And lastly, make tmp and var/tmp noexec again

    mount -v -o remount,noexec /tmp
    mount -v -o remount,noexec /var/tmp