diff --git a/src/Gateways/Alipay/Support.php b/src/Gateways/Alipay/Support.php
index 1a3f46a96..b0895fb4c 100644
--- a/src/Gateways/Alipay/Support.php
+++ b/src/Gateways/Alipay/Support.php
@@ -156,7 +156,9 @@ public static function generateSign(array $params): string
         }
 
         if (Str::endsWith($privateKey, '.pem')) {
-            $privateKey = openssl_pkey_get_private($privateKey);
+            $privateKey = openssl_pkey_get_private(
+                Str::startsWith($privateKey, 'file://') ? $privateKey : 'file://'.$privateKey
+            );
         } else {
             $privateKey = "-----BEGIN RSA PRIVATE KEY-----\n".
                 wordwrap($privateKey, 64, "\n", true).