diff --git a/src/Controller/WarrantyController.php b/src/Controller/WarrantyController.php
index 05cba708..1c41ccfa 100644
--- a/src/Controller/WarrantyController.php
+++ b/src/Controller/WarrantyController.php
@@ -163,9 +163,14 @@ class WarrantyController extends Controller
         $date_claim = DateTime::createFromFormat('d M Y', $req->request->get('date_claim'));
         $date_expire = DateTime::createFromFormat('d M Y', $req->request->get('date_expire'));
 
+        // get serial. Set to null if empty
+        if (empty($req->request->get('serial')))
+            $obj->setSerial();
+        else
+            $obj->setSerial($req->request->get('serial'));
+
         // set and save values
-        $obj->setSerial($req->request->get('serial'))
-            ->setWarrantyClass($req->request->get('warranty_class'))
+        $obj->setWarrantyClass($req->request->get('warranty_class'))
             ->setFirstName($req->request->get('first_name'))
             ->setLastName($req->request->get('last_name'))
             ->setMobileNumber($req->request->get('mobile_number'))
@@ -325,9 +330,14 @@ class WarrantyController extends Controller
         $date_claim = DateTime::createFromFormat('d M Y', $req->request->get('date_claim'));
         $date_expire = DateTime::createFromFormat('d M Y', $req->request->get('date_expire'));
 
+        // get serial. Set to null if empty
+        if (empty($req->request->get('serial')))
+            $obj->setSerial();
+        else
+            $obj->setSerial($req->request->get('serial'));
+
         // set and save values
-        $obj->setSerial($req->request->get('serial'))
-            ->setWarrantyClass($req->request->get('warranty_class'))
+        $obj->setWarrantyClass($req->request->get('warranty_class'))
             ->setFirstName($req->request->get('first_name'))
             ->setLastName($req->request->get('last_name'))
             ->setMobileNumber($req->request->get('mobile_number'))