diff --git a/wx/V3/WxV3PaymentTait.php b/wx/V3/WxV3PaymentTait.php
index ff3f680..c433f84 100644
--- a/wx/V3/WxV3PaymentTait.php
+++ b/wx/V3/WxV3PaymentTait.php
@@ -73,7 +73,7 @@ trait WxV3PaymentTait
     {
         $config = $this->getPayConfig();
 
-        $sign = $this->signature('POST', '/v3/pay/transactions/out-trade-no/' . $orderNo . '?mchid=' . $config->pay->wx->mchId, null);
+        $sign = $this->signature('POST', '/v3/pay/transactions/out-trade-no/' . $orderNo . '?mchid=' . $config->pay->wx->mchId, "");
 
         $client = $this->createClient($sign, null);
         $client->get('/v3/pay/transactions/out-trade-no/' . $orderNo, ['mchid' => $config->pay->wx->mchId]);