diff --git a/src/Middleware/InternalApi.php b/src/Middleware/InternalApi.php
index 41f340a..dbd520b 100644
--- a/src/Middleware/InternalApi.php
+++ b/src/Middleware/InternalApi.php
@@ -9,6 +9,11 @@ use Illuminate\Support\Str;
 class InternalApi
 {
 
+    public function __construct()
+    {
+        app()->configure('internal_api');
+    }
+
     /**
      * Handle an incoming request.
      *
@@ -54,8 +59,7 @@ class InternalApi
 
     protected function sign($params)
     {
-        $app = $params['appid'];
-        $key = config('internal_api.server.' . $app);
+        $key = config('internal_api.server.' . $params['appid']);
         unset($params['sign']);
         ksort($params);
         $str = http_build_query($params, null, '&');