diff --git a/src/Model/Message/MessageBag.php b/src/Model/Message/MessageBag.php
index 63c33900..4ff2c38d 100644
--- a/src/Model/Message/MessageBag.php
+++ b/src/Model/Message/MessageBag.php
@@ -51,7 +51,7 @@ public function with(MessageInterface $message): self
     public function merge(MessageBag $messageBag): self
     {
         $messages = clone $this;
-        $messages->messages = array_merge($messages->messages, $messageBag->messages);
+        $messages->messages = array_merge($messages->messages, $messageBag->getMessages());
 
         return $messages;
     }