diff --git a/src/PHPMailer.php b/src/PHPMailer.php
index 3c3e6380..4a46a4df 100644
--- a/src/PHPMailer.php
+++ b/src/PHPMailer.php
@@ -3772,27 +3772,9 @@ class PHPMailer
         } else {
             $privKey = openssl_pkey_get_private($privKeyStr);
         }
-        //Workaround for missing digest algorithms in old PHP & OpenSSL versions
-        //@link http://stackoverflow.com/a/11117338/333340
-        if (version_compare(PHP_VERSION, '5.3.0') >= 0 and
-            in_array('sha256WithRSAEncryption', openssl_get_md_methods(true))) {
-            if (openssl_sign($signHeader, $signature, $privKey, 'sha256WithRSAEncryption')) {
-                openssl_pkey_free($privKey);
-                return base64_encode($signature);
-            }
-        } else {
-            $pinfo = openssl_pkey_get_details($privKey);
-            $hash = hash('sha256', $signHeader);
-            //'Magic' constant for SHA256 from RFC3447
-            //@link https://tools.ietf.org/html/rfc3447#page-43
-            $t = '3031300d060960864801650304020105000420' . $hash;
-            $pslen = $pinfo['bits'] / 8 - (strlen($t) / 2 + 3);
-            $eb = pack('H*', '0001' . str_repeat('FF', $pslen) . '00' . $t);
-
-            if (openssl_private_encrypt($eb, $signature, $privKey, OPENSSL_NO_PADDING)) {
-                openssl_pkey_free($privKey);
-                return base64_encode($signature);
-            }
+        if (openssl_sign($signHeader, $signature, $privKey, 'sha256WithRSAEncryption')) {
+            openssl_pkey_free($privKey);
+            return base64_encode($signature);
         }
         openssl_pkey_free($privKey);
         return '';