diff --git a/app/Http/Controllers/PdfController.php b/app/Http/Controllers/PdfController.php
index 8856cdb..a3bd0b7 100644
--- a/app/Http/Controllers/PdfController.php
+++ b/app/Http/Controllers/PdfController.php
@@ -913,6 +913,11 @@ class PdfController extends Controller
         $itemCharacteristicId = $request->query('item_characteristic_id');
         $stickerId = trim($stickerId);
 
+        // Normalize "empty" or "" to null
+        $plantId = ($plantId && $plantId != 'empty') ? $plantId : null;
+        $itemCharacteristicId = ($itemCharacteristicId && $itemCharacteristicId != 'empty') ? $itemCharacteristicId : null;
+
+
         if ($plantId && $itemCharacteristicId)
         {
             $plantId = $request->query('plant_id');