diff --git a/src/plugin/admin/app/controller/Crud.php b/src/plugin/admin/app/controller/Crud.php
index 4b75559..316d5bc 100644
--- a/src/plugin/admin/app/controller/Crud.php
+++ b/src/plugin/admin/app/controller/Crud.php
@@ -128,7 +128,7 @@ protected function selectInput(Request $request): array
      * @param string $order
      * @return EloquentBuilder|QueryBuilder|Model
      */
-    protected function doSelect(array $where, string $field = null, string $order= 'desc')
+    protected function doSelect(array $where, ?string $field = null, string $order= 'desc')
     {
         $model = $this->model;
         foreach ($where as $column => $value) {
diff --git a/src/plugin/admin/app/controller/PluginController.php b/src/plugin/admin/app/controller/PluginController.php
index e31479a..6207219 100644
--- a/src/plugin/admin/app/controller/PluginController.php
+++ b/src/plugin/admin/app/controller/PluginController.php
@@ -508,7 +508,7 @@ protected function downloadClient(): Client
      * @param array $extraDirs
      * @return mixed|string|null
      */
-    protected function findCmd(string $name, string $default = null, array $extraDirs = [])
+    protected function findCmd(string $name, ?string $default = null, array $extraDirs = [])
     {
         if (ini_get('open_basedir')) {
             $searchPath = array_merge(explode(PATH_SEPARATOR, ini_get('open_basedir')), $extraDirs);