diff --git a/library/think/Db.php b/library/think/Db.php
index 7edb6ed4..ea0071a8 100644
--- a/library/think/Db.php
+++ b/library/think/Db.php
@@ -89,7 +89,7 @@ class Db
         return self::$instance[$name];
     }
     
-    public static function clear(){
+    public static function clear() {
         self::$instance = null;
     }