diff --git a/source/packages/plg_system_mokosuitefield/src/Helper/WarrantyHelper.php b/source/packages/plg_system_mokosuitefield/src/Helper/WarrantyHelper.php
index c1f3eb0..093fef5 100644
--- a/source/packages/plg_system_mokosuitefield/src/Helper/WarrantyHelper.php
+++ b/source/packages/plg_system_mokosuitefield/src/Helper/WarrantyHelper.php
@@ -54,9 +54,16 @@ class WarrantyHelper
 	{
 		$warranty = self::checkWarranty($equipmentId);
 
-		if (!$warranty->found ?? true) return (object) ['success' => false, 'error' => 'Equipment not found'];
+		if (empty($warranty->id)) return (object) ['success' => false, 'error' => 'Equipment not found'];
 		if (!$warranty->under_warranty) return (object) ['success' => false, 'error' => 'Warranty expired'];
 
+		// Verify work order exists and is linked to this equipment
+		$db->setQuery($db->getQuery(true)->select('id')->from('#__mokosuitefield_work_orders')
+			->where('id = ' . (int) $woId));
+		if (!(int) $db->loadResult()) {
+			return (object) ['success' => false, 'error' => 'Invalid work order'];
+		}
+
 		$db = Factory::getContainer()->get(DatabaseInterface::class);
 		$now = Factory::getDate()->toSql();