diff --git a/client/api/ApiCallbackMessage.ts b/client/api/ApiCallbackMessage.ts
index 4d29aa1..dc4f58f 100644
--- a/client/api/ApiCallbackMessage.ts
+++ b/client/api/ApiCallbackMessage.ts
@@ -1,6 +1,3 @@
-type ErrorCausedBy =
-    'NOT_IN_THIS_CHAT_MEMBER_LIST'
-
 type ApiCallbackMessage = {
     msg: string,
     /**
@@ -14,6 +11,5 @@ type ApiCallbackMessage = {
      */
     code: 200 | 400 | 401 | 403 | 404 | 500 | 501 | -1,
     data?: { [key: string]: unknown },
-    caused_by?: ErrorCausedBy,
 }
 export default ApiCallbackMessage
diff --git a/server/api/ApiCallbackMessage.ts b/server/api/ApiCallbackMessage.ts
index d66a0e9..e94b2df 100644
--- a/server/api/ApiCallbackMessage.ts
+++ b/server/api/ApiCallbackMessage.ts
@@ -1,6 +1,3 @@
-type ErrorCausedBy =
-    'NOT_IN_THIS_CHAT_MEMBER_LIST'
-
 type ApiCallbackMessage = {
     msg: string,
     /**
@@ -14,6 +11,5 @@ type ApiCallbackMessage = {
      */
     code: 200 | 400 | 401 | 403 | 404 | 500 | 501,
     data?: { [key: string]: unknown },
-    caused_by?: ErrorCausedBy,
 }
 export default ApiCallbackMessage