diff --git a/src/sql/resolver/expr/ob_raw_expr_util.cpp b/src/sql/resolver/expr/ob_raw_expr_util.cpp
index 9fb6b3455a..dc660d3bae 100644
--- a/src/sql/resolver/expr/ob_raw_expr_util.cpp
+++ b/src/sql/resolver/expr/ob_raw_expr_util.cpp
@@ -6489,7 +6489,7 @@ int ObRawExprUtils::check_composite_cast(ObRawExpr *&expr, ObSchemaChecker &sche
     } else if (ObExtendType == obj_type
                && OB_INVALID_ID != udt_id
                && !(src->get_expr_type() == T_QUESTIONMARK ||
-                    (src->get_expr_type() == T_FUN_SYS_CAST
+                    (udt_id == T_OBJ_XML && src->get_expr_type() == T_FUN_SYS_CAST
                     && src->get_param_expr(0)->get_expr_type() == T_QUESTIONMARK))) {
       if (ObNullType == src->get_result_type().get_type()) {
         // do nothing