diff --git a/src/main/java/com/alibaba/druid/sql/ast/statement/SQLJoinTableSource.java b/src/main/java/com/alibaba/druid/sql/ast/statement/SQLJoinTableSource.java
index 932054b8c1..8812185a38 100644
--- a/src/main/java/com/alibaba/druid/sql/ast/statement/SQLJoinTableSource.java
+++ b/src/main/java/com/alibaba/druid/sql/ast/statement/SQLJoinTableSource.java
@@ -271,7 +271,7 @@ public class SQLJoinTableSource extends SQLTableSourceImpl implements SQLReplace
         }
 
         if(condition != null){
-            x.setCondition(condition);
+            x.setCondition(condition.clone());
         }
 
         for (SQLExpr item : using) {