diff -u b/core/includes/theme.inc b/core/includes/theme.inc
--- b/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -2007,12 +2007,13 @@
   // to theme the page depending on the current path (e.g. node, admin, user,
   // etc.) as well as more specific data like path-frontpage or
   // path-contenttype.
-  $path = arg();
-  if(empty($path['0'])) {
+
+  if(drupal_is_front_page()){
     $body_classes[] = 'path-frontpage';
   }
-  else {
-    $body_classes[] = 'path-' . $path['0'];
+  if(request_path()){
+    $path = explode("/", request_path());
+    $body_classes[] = 'path-' . $path[0];
   }
 
   $variables['attributes']['class'] = $body_classes;