diff --git a/src/Vimeo/Upload/TusClient.php b/src/Vimeo/Upload/TusClient.php
index beb4e32..f1096ee 100644
--- a/src/Vimeo/Upload/TusClient.php
+++ b/src/Vimeo/Upload/TusClient.php
@@ -9,10 +9,10 @@ class TusClient extends \TusPhp\Tus\Client
 {
     /**
      * Sets the url for retrieving the TUS upload.
-     * @param string $url
+     * @param string|null $url
      * @return $this
      */
-    public function setUrl(string $url)
+    public function setUrl(?string $url)
     {
         $this->url = $url;
         return $this;
diff --git a/src/Vimeo/Upload/TusClientFactory.php b/src/Vimeo/Upload/TusClientFactory.php
index 4d8ac7f..f3fc36b 100644
--- a/src/Vimeo/Upload/TusClientFactory.php
+++ b/src/Vimeo/Upload/TusClientFactory.php
@@ -8,10 +8,10 @@ class TusClientFactory
 {
     /**
      * @param string $base_uri The fully qualified domain of the upload, ex: https://us-files.tus.vimeo.com
-     * @param string $url The fully qualified url of the upload, ex: https://us-files.tus.vimeo.com/files/vimeo-a1b2c3d4
+     * @param string|null $url The fully qualified url of the upload, ex: https://us-files.tus.vimeo.com/files/vimeo-a1b2c3d4
      * @return Client
      */
-    public function getTusClient(string $base_uri, string $url) : Client
+    public function getTusClient(string $base_uri, ?string $url) : Client
     {
         $client = new TusClient($base_uri);
         $client->setUrl($url);