Imagemagick toolkit throws error

When I enable the imagemagick framework, I get a blank page under /admin/settings. This is the PHP error that shows up in my logs.

PHP Fatal error: Call to undefined function form_textfield() in /var/www/www.domain.com/includes/image.imagemagick.inc on line 22

I compiled PHP with the folllowing settings:

'./configure' '--with-litespeed' '--with-config-file-path=../conf' '--with-mysql' '--disable-ipv6' '--without-sqlite' '--disable-hash' '--disable-filter' '--disable-json' '--without-pdo-sqlite' '--disable-pdo' '--disable-simplexml' '--disable-spl' '--enable-mbstring' '--with-openssl' '--with-gd' '--with-zlib' '--with-jpeg-dir=../jpeg-6b/'

Thanks!