diff --git a/application/controllers/api/frontend/v1/Documents.php b/application/controllers/api/frontend/v1/Documents.php
index dcc0bb9ac..13c0a2eba 100644
--- a/application/controllers/api/frontend/v1/Documents.php
+++ b/application/controllers/api/frontend/v1/Documents.php
@@ -220,7 +220,7 @@ class Documents extends FHCAPI_Controller
 			'gedruckt' => true,
 			'insertamum' => date('c'),
 			'insertvon' => getAuthUID(),
-			'uid' => $this->input->post_get('uid') ?: '',
+			'uid' => $this->input->post_get('uid') ?: null,
 			'archiv' => true,
 			'signiert' => !!$sign_user,
 			'stud_selfservice' => $vorlage->stud_selfservice
@@ -334,6 +334,7 @@ class Documents extends FHCAPI_Controller
 			if ($prestudent_id) {
 				$this->load->model('crm/prestudent_model', 'PrestudentModel');
 				$this->PrestudentModel->addJoin('public.tbl_studiengang', 'studiengang_kz', 'LEFT');
+				$this->PrestudentModel->addSelect('tbl_prestudent.*, UPPER(typ || kurzbz) AS kuerzel');
 				$result = $this->PrestudentModel->load($prestudent_id);
 				$prestudent = current($this->getDataOrTerminateWithError($result));