diff --git a/src/RabbitQueue.php b/src/RabbitQueue.php
index 387e3da..62dcff1 100644
--- a/src/RabbitQueue.php
+++ b/src/RabbitQueue.php
@@ -400,7 +400,7 @@ private function createMessage($payload, int $attempts = 2): array
         ];
     }
 
-    private function publishProperties(string $queue = '', array $options = []): array
+    private function publishProperties(?string $queue = '', array $options = []): array
     {
         $queue = $this->getQueue($queue);
         $attempts = Arr::get($options, 'attempts') ?: 0;