diff --git a/code/cms/DMSDocumentAddController.php b/code/cms/DMSDocumentAddController.php
index dcba191..d3d2e76 100644
--- a/code/cms/DMSDocumentAddController.php
+++ b/code/cms/DMSDocumentAddController.php
@@ -211,8 +211,8 @@ class DMSDocumentAddController extends LeftAndMain
     {
         return Controller::join_links(
             CMSPageEditController::singleton()->getEditForm($pageId)->FormAction(),
-            'field/Document Sets/item',
-            $documentSetId
+            'field/DocumentSets/item',
+            (int) $documentSetId
         );
     }