diff --git a/class.phpmailer.php b/class.phpmailer.php
index e7c62315..31a290f5 100644
--- a/class.phpmailer.php
+++ b/class.phpmailer.php
@@ -1834,7 +1834,6 @@ class PHPMailer
         return $this->MIMEHeader . $this->mailHeader . self::CRLF . $this->MIMEBody;
     }
 
-
     /**
      * Assemble the message body.
      * Returns an empty string on failure.
@@ -1973,16 +1972,27 @@ class PHPMailer
                     throw new phpmailerException($this->lang('signing') . ' Could not write temp file');
                 }
                 $signed = tempnam(sys_get_temp_dir(), 'signed');
-                if (@openssl_pkcs7_sign(
-                    $file,
-                    $signed,
-                    'file://' . realpath($this->sign_cert_file),
-                    array('file://' . realpath($this->sign_key_file), $this->sign_key_pass),
-                    null,
-                    PKCS7_DETACHED,
-                    $this->sign_extracerts_file
-                )
-                ) {
+                //Workaround for PHP bug https://bugs.php.net/bug.php?id=69197
+                if (empty($this->sign_extracerts_file)) {
+                    $sign = @openssl_pkcs7_sign(
+                        $file,
+                        $signed,
+                        'file://' . realpath($this->sign_cert_file),
+                        array('file://' . realpath($this->sign_key_file), $this->sign_key_pass),
+                        null
+                    );
+                } else {
+                    $sign = @openssl_pkcs7_sign(
+                        $file,
+                        $signed,
+                        'file://' . realpath($this->sign_cert_file),
+                        array('file://' . realpath($this->sign_key_file), $this->sign_key_pass),
+                        null,
+                        PKCS7_DETACHED,
+                        $this->sign_extracerts_file
+                    );
+                }
+                if ($sign) {
                     @unlink($file);
                     $body = file_get_contents($signed);
                     @unlink($signed);