diff --git a/wx/V3/WxV3PaymentNotify.php b/wx/V3/WxV3PaymentNotify.php
index f6638f7..0aec437 100644
--- a/wx/V3/WxV3PaymentNotify.php
+++ b/wx/V3/WxV3PaymentNotify.php
@@ -111,7 +111,7 @@ class WxV3PaymentNotify extends SmallProgram
      */
     protected function rsaFrom(string $thing, string $type = KEY_TYPE_PRIVATE): OpenSSLAsymmetricKey
     {
-        $pkey = (($isPublic = $type === KEY_TYPE_PUBLIC) ? openssl_pkey_get_public(file_get_contents($thing)) : openssl_pkey_get_private(file_get_contents($thing)));
+        $pkey = (($isPublic = $type === KEY_TYPE_PUBLIC) ? openssl_pkey_get_public('file:/' . $thing) : openssl_pkey_get_private('file:/' . $thing));
         if (false === $pkey) {
             throw new \UnexpectedValueException(sprintf('Cannot load %s from(%s), please take care about the $thing input.', $isPublic ? 'publicKey' : 'privateKey', gettype($thing)));
         }