diff --git a/library/think/model/Relation.php b/library/think/model/Relation.php
index 22223281..39d62871 100644
--- a/library/think/model/Relation.php
+++ b/library/think/model/Relation.php
@@ -12,6 +12,7 @@
 namespace think\model;
 
 use think\db\Query;
+use think\Exception;
 
 abstract class Relation
 {