Problem using jpeg-support within gdlib

Hi, how can I enable jpeg-support within gdlib. The output of gd_info() is the following: array(11) { ["GD Version"]=> string(27) "bundled (2.0.28 compatible)" ["FreeType Support"]=> bool(true) ["FreeType Linkage"]=> string(13) "with freetype" ["T1Lib Support"]=> bool(false) ["GIF Read Support"]=> bool(true) ["GIF Create Support"]=> bool(true) ["JPG Support"]=> bool(false) ["PNG Support"]=> bool(true) ["WBMP Support"]=> bool(true) ["XBM Support"]=> bool(true) ["JIS-mapped Japanese Font Support"]=> bool(false) } Only the support for jpeg I miss. I see that ttf and all other graphicformats are enabled. Regards, Ruprecht