Cron - PHP: Call to undefined function: gzinflate()

[safoo]

I have a php script that I need run daily. The script works through the browser, but when the cron didn't seem to be executing the file, I tried running the script from the shell and get the following error:

Fatal error: Call to undefined function: gzinflate()

I am using /root/ispconfig/php/php to run the script. I know that the ispconfig php is slightly different than what is run when the file is executed from the browser, but I was hoping zlib support can be added at runtime? Hopefully someone can point me in the right direction.