diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 78d0ee3..865ce96 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -2286,9 +2286,10 @@ function template_preprocess_tablesort_indicator(&$variables) {
   }
   // Build the attributes to the indicator image.
   $attributes = array(
+    'typeof' => array('foaf:Image'),
+    'src' => file_create_url($variables['uri']),
     'width' => 13,
     'height' => 13,
-    'src' => file_create_url($variables['uri']),
     'alt' => $alt_title,
     'title' => $alt_title,
   );