diff --git a/src/Resources/MessagesResource.php b/src/Resources/MessagesResource.php
index f24f4cf..15efded 100644
--- a/src/Resources/MessagesResource.php
+++ b/src/Resources/MessagesResource.php
@@ -16,7 +16,7 @@ class MessagesResource extends APIResource
 
     private int $maxTokens;
 
-    private array $messages;
+    private array $messages = [];
 
     private ?string $system = null;