diff --git a/classes/framework.php b/classes/framework.php
index a43597ab86e64d12528e6ce2256f3c20cb8278d1..ee5ab5c534cb9737f5c8f37d7177a5da9dd5aa3b 100644
--- a/classes/framework.php
+++ b/classes/framework.php
@@ -1123,7 +1123,7 @@ class framework implements \H5PFrameworkInterface {
         return (int) $DB->get_field_sql(
                 "SELECT COUNT(id)
                    FROM {hvp}
-                  WHERE filtered = ''");
+                  WHERE filtered LIKE ''");
     }
 
     /**