diff --git a/src/api2/backup.rs b/src/api2/backup.rs
index abe247b9..13463716 100644
--- a/src/api2/backup.rs
+++ b/src/api2/backup.rs
@@ -6,7 +6,7 @@ use hyper::{Body, Response, StatusCode};
 use serde_json::{json, Value};
 
 use proxmox::{sortable, identity};
-use proxmox::api::{api, list_subdirs_api_method};
+use proxmox::api::list_subdirs_api_method;
 use proxmox::api::{ApiFuture, ApiHandler, ApiMethod, Router, RpcEnvironment};
 use proxmox::api::router::SubdirMap;
 use proxmox::api::schema::*;
@@ -216,18 +216,20 @@ pub const BACKUP_API_ROUTER: Router = Router::new()
     .get(&list_subdirs_api_method!(BACKUP_API_SUBDIRS))
     .subdirs(BACKUP_API_SUBDIRS);
 
-#[api(
-    input: {
-        properties: {
-            "archive-name": {
-                schema: crate::api2::types::BACKUP_ARCHIVE_NAME_SCHEMA,
-            },
-        },
-    },
-)]
-/// Create dynamic chunk index file.
+#[sortable]
+pub const API_METHOD_CREATE_DYNAMIC_INDEX: ApiMethod = ApiMethod::new(
+    &ApiHandler::Sync(&create_dynamic_index),
+    &ObjectSchema::new(
+        "Create dynamic chunk index file.",
+        &sorted!([
+            ("archive-name", false, &crate::api2::types::BACKUP_ARCHIVE_NAME_SCHEMA),
+        ]),
+    )
+);
+
 fn create_dynamic_index(
     param: Value,
+    _info: &ApiMethod,
     rpcenv: &mut dyn RpcEnvironment,
 ) -> Result<Value, Error> {