diff --git a/src/FedoraApi.php b/src/FedoraApi.php
index 60b9b13..818db0d 100644
--- a/src/FedoraApi.php
+++ b/src/FedoraApi.php
@@ -387,7 +387,7 @@ public function createTransaction()
     public function extendTransaction($id)
     {
         $options = ['http_errors' => false];
-        $uri = $this->generateTransactionUri($id);
+        $uri = $this->generateTransactionUri($id) . '/fcr:tx';
         return $this->client->request(
             'POST',
             $uri,