diff --git a/phpseclib/Crypt/Common/PrivateKey.php b/phpseclib/Crypt/Common/PrivateKey.php
index 00712328..bc0b9ede 100644
--- a/phpseclib/Crypt/Common/PrivateKey.php
+++ b/phpseclib/Crypt/Common/PrivateKey.php
@@ -26,5 +26,5 @@ interface PrivateKey
     //public function decrypt($ciphertext);
     public function getPublicKey();
     public function toString($type, array $options = []);
-    public function withPassword($string);
+    public function withPassword($string = false);
 }
diff --git a/phpseclib/File/X509.php b/phpseclib/File/X509.php
index 2e1620c1..daf54796 100644
--- a/phpseclib/File/X509.php
+++ b/phpseclib/File/X509.php
@@ -2615,7 +2615,7 @@ class X509
         if ($signatureAlgorithm != 'id-RSASSA-PSS') {
             $signatureAlgorithm = ['algorithm' => $signatureAlgorithm];
         } else {
-            $r = PSS::load($issuer->privateKey->toString('PSS'));
+            $r = PSS::load($issuer->privateKey->withPassword()->toString('PSS'));
             $signatureAlgorithm = [
                 'algorithm' => 'id-RSASSA-PSS',
                 'parameters' => PSS::savePSSParams($r)