diff --git a/src/Manager.php b/src/Manager.php
index 03f9e29..ee3aded 100644
--- a/src/Manager.php
+++ b/src/Manager.php
@@ -51,7 +51,7 @@ public function __construct(Container $app, Factory $factory)
      *
      * @return \Elasticsearch\Client
      */
-    public function connection(string $name = null): Client
+    public function connection(?string $name = null): Client
     {
         $name = $name ?: $this->getDefaultConnection();