diff --git a/includes/theme.inc b/includes/theme.inc
index 1e576f3584a20cd2ad8d2de806cac8ea4ed41dc7..79392b76520f39b2f0c35cad87d4d1958e2a3cdb 100644
--- a/includes/theme.inc
+++ b/includes/theme.inc
@@ -398,7 +398,7 @@ function theme_page($content) {
function theme_maintenance_page($content, $messages = TRUE, $partial = FALSE) {
drupal_set_header('Content-Type: text/html; charset=utf-8');
- theme('add_style', 'misc/maintenance.css');
+ drupal_add_css('misc/maintenance.css', 'core');
drupal_set_html_head('<link rel="shortcut icon" href="'. base_path() .'misc/favicon.ico" type="image/x-icon" />');
$output = "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\n";
@@ -428,7 +428,7 @@ function theme_maintenance_page($content, $messages = TRUE, $partial = FALSE) {
function theme_install_page($content) {
drupal_set_header('Content-Type: text/html; charset=utf-8');
- theme('add_style', 'misc/maintenance.css');
+ drupal_add_css('misc/maintenance.css', 'core');
drupal_set_html_head('<link rel="shortcut icon" href="'. base_path() .'misc/favicon.ico" type="image/x-icon" />');
$output = "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\n";
$output .= '<html xmlns="http://www.w3.org/1999/xhtml">';