how i relax php's open_basedir restriction?

boundary files uninterrupted php within directory-tree.

i am storing several category libraries settlement files outmost web bottom directory. proceed web server does publicly accessible. however i try consolidate concentration i an open_basedir limitation blunder this:

warning: realpath()
[function.realpath]: open_basedir
limitation effect.
file(/var/www/vhosts/domain.tld/zend/application)
within certified path(s):
(/var/www/vhosts/domain.tld/httpdocs:/tmp)
in
/var/www/vhosts/domain.tld/httpdocs/index.php
line 5

my web bottom here:

/var/www/vhosts/domain.tld/httpdocs

my libraries settlement office here:

/var/www/vhosts/domain.tld/zend

what best workaround relax open_basedir limitation the office tree underneath domain folder becomes accessible application? i have array domains i wish with, i'm also apparently heedful formulating confidence vulnerabilities.

note: i am controlling centos, apache, plesk, i have bottom ssh opening server. nonetheless doesn't ask zend horizon directly, i am controlling instance. here inclusion zend's bootstrap:

define('application_path', realpath(dirname(__file__) . '/../zend/application/'));
set_include_path(application_path . '/../zend/library' . path_separator . get_include_path());