allow Contributors to upload?

Is it possible to allow Contributors to change their profile photo? I found this code snippet that can be added to functions.php but it doesn’t seem to be having an effect:

if ( current_user_can('contributor') && !current_user_can('upload_files') )
add_action('admin_init', 'allow_contributor_uploads');

function allow_contributor_uploads() {
$contributor = get_role('contributor');
$contributor->add_cap('upload_files');
}

Thanks for your help!