diff --git a/lib/grade/grade_item.php b/lib/grade/grade_item.php
index a8690f6..d0989b7 100644
--- a/lib/grade/grade_item.php
+++ b/lib/grade/grade_item.php
@@ -1339,7 +1339,7 @@ class grade_item extends grade_object {
                                AND gi.categoryid IN (
                                   SELECT gc.id
                                     FROM {grade_categories} gc
-                                   WHERE gc.path LIKE '%?%')";
+                                   WHERE gc.path LIKE '%/?/%')";
 
             } else {
                 $params[] = $grade_category->id;