diff --git a/src/Helpers/DeliveryCalc.php b/src/Helpers/DeliveryCalc.php
index a556a31..d8aec52 100644
--- a/src/Helpers/DeliveryCalc.php
+++ b/src/Helpers/DeliveryCalc.php
@@ -181,8 +181,9 @@ static function ($carry, $item) use ($package) {
                 $deliveryParam['type']        = Tariff::getTariffType($deliveryParam['tariff_code']);
 
                 $serviceList = Helper::getServices($deliveryMethod, $deliveryParam['tariff_code']);
+
                 if (!empty($serviceList)) {
-                    $deliveryParam['services'] = $serviceList;
+                    $deliveryParam['services'] = array_merge($serviceList, $deliveryParam['services']);
                 }
 
                 $tariffInfo = $api->calculateTariff($deliveryParam);