diff --git a/convention.php b/convention.php
index fc4583a4..700db0fa 100644
--- a/convention.php
+++ b/convention.php
@@ -46,6 +46,8 @@ return [
     'action_bind_class'     => false,
     'url_module_map'        => [],
     'response_exit'         => true,
+    'default_lang'          => 'zh-cn',
+    'use_session'           => false,
 
     /* 错误设置 */
     //错误显示信息,非调试模式有效
diff --git a/library/think/lang.php b/library/think/lang.php
index c5581fa4..527c2b3f 100644
--- a/library/think/lang.php
+++ b/library/think/lang.php
@@ -35,6 +35,9 @@ class Lang
     {
         $range = $range ? $range : self::$range;
         // 批量定义
+        if (!isset(self::$lang[$range])) {
+            self::$lang[$range] = [];
+        }
         if (is_array($name)) {
             return self::$lang[$range] = array_merge(self::$lang[$range], array_change_key_case($name));
         } else {
@@ -52,6 +55,9 @@ class Lang
     {
         $range = $range ? $range : self::$range;
         $lang  = is_file($file) ? include $file : [];
+        if (!isset(self::$lang[$range])) {
+            self::$lang[$range] = [];
+        }
         // 批量定义
         return self::$lang[$range] = array_merge(self::$lang[$range], array_change_key_case($lang));
     }