diff --git a/src/Client.php b/src/Client.php
index b38d876..65c5088 100644
--- a/src/Client.php
+++ b/src/Client.php
@@ -690,7 +690,7 @@ public function listFiles(array $options)
                 'headers' => [
                     'Authorization' => $this->authToken
                 ],
-                'json' => [
+                'json' => $options + [
                     'bucketId' => $options['BucketId'],
                     'startFileName' => $nextFileName,
                     'maxFileCount' => $maxFileCount,