Add_theme_support in Frontpage.php adds a feature for the whole Wordpress site

I just want to display a footer on the front page of my website. To do this I tried adding the following lines in my front_page.php inside my Wordpress theme folder:

if (is_front_page())
{add_theme_support( 'genesis-footer-widgets', 3 );}

Even though I restricted it to the front_page, the footer gets displayed on all pages. How can I limit the footer for the frontpage only?