diff --git a/includes/common.inc b/includes/common.inc
index d2b9c24926b6806ad116ce334e35b1ec8969d134..644947f5d0a174b6045ad60a113de42820cd3553 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -2758,7 +2758,7 @@ function drupal_get_css($css = NULL) {
     $css = drupal_add_css();
   }
 
-  // Allow modules to alter the CSS items.
+  // Allow modules and themes to alter the CSS items.
   drupal_alter('css', $css);
 
   // Sort CSS items according to their weights.