diff --git a/doc/api/garage-admin-v0.yml b/doc/api/garage-admin-v0.yml
index 9e419513..a9d50b42 100644
--- a/doc/api/garage-admin-v0.yml
+++ b/doc/api/garage-admin-v0.yml
@@ -108,6 +108,7 @@ paths:
                       example: true
                     error:
                       type: string
+                      nullable: true
                       example: 
                 
   /layout: