remove website field on comment form

Hello

as to the info I found the following code is supposed to remove the "website" field on the post comment form - however, the field still shows - any ideas??

/* Remove website (url) field on comment form
---------------------------------------------------------------------------- */
function themeprefix_disable_comment_url($fields) { 
    unset($fields['url']);
   
	return $fields;
}
add_filter('comment_form_default_fields', 'themeprefix_disable_comment_url');