diff --git a/Exception/DelayedMessageHandlingException.php b/Exception/DelayedMessageHandlingException.php
index 3b81150b..10dc9fce 100644
--- a/Exception/DelayedMessageHandlingException.php
+++ b/Exception/DelayedMessageHandlingException.php
@@ -23,9 +23,10 @@ class DelayedMessageHandlingException extends RuntimeException implements Wrappe
 {
     use WrappedExceptionsTrait;
 
-    private Envelope $envelope;
+    private array $exceptions;
+    private ?Envelope $envelope;
 
-    public function __construct(array $exceptions, Envelope $envelope)
+    public function __construct(array $exceptions, Envelope $envelope = null)
     {
         $this->envelope = $envelope;
 
@@ -55,7 +56,7 @@ public function getExceptions(): array
         return $this->exceptions;
     }
 
-    public function getEnvelope(): Envelope
+    public function getEnvelope(): ?Envelope
     {
         return $this->envelope;
     }
diff --git a/Tests/Stamp/StringErrorCodeException.php b/Tests/Stamp/StringErrorCodeException.php
deleted file mode 100644
index 63d6f88e..00000000
--- a/Tests/Stamp/StringErrorCodeException.php
+++ /dev/null
@@ -1,21 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\Messenger\Tests\Stamp;
-
-class StringErrorCodeException extends \Exception
-{
-    public function __construct(string $message, string $code)
-    {
-        parent::__construct($message);
-        $this->code = $code;
-    }
-}
diff --git a/Worker.php b/Worker.php
index 3dc85b52..eb0af634 100644
--- a/Worker.php
+++ b/Worker.php
@@ -189,7 +189,7 @@ private function ack(): bool
                     $receiver->reject($envelope);
                 }
 
-                if ($e instanceof HandlerFailedException || $e instanceof DelayedMessageHandlingException) {
+                if ($e instanceof HandlerFailedException || ($e instanceof DelayedMessageHandlingException && null !== $e->getEnvelope())) {
                     $envelope = $e->getEnvelope();
                 }