diff --git a/proto/models/member.proto b/proto/models/member.proto
index c3d2556..675f1de 100644
--- a/proto/models/member.proto
+++ b/proto/models/member.proto
@@ -47,7 +47,7 @@ message ParentMemberModel {
   bet.beteran.member_class.MemberClass member_class = 3;
   bet.beteran.member_level.MemberLevel member_level = 4;
   optional bet.beteran.member_bank_account.MemberBankAccountModel bank_account = 5;
-  optional Member parent_member = 6;
+  optional string parent_member_id = 6;
   uint64 child_member_count = 7;
   string username = 8;
   string nickname = 9;