diff --git a/server/gameserver/roommgr.cc b/server/gameserver/roommgr.cc
index 46b4bdd6..47581ac8 100644
--- a/server/gameserver/roommgr.cc
+++ b/server/gameserver/roommgr.cc
@@ -76,6 +76,13 @@ void RoomMgr::_CMJoin(f8::MsgHdr* hdr, const cs::CMJoin& msg)
         JoinErrorHandle(msg, 2, hdr->socket_handle);
         return;
     }
+    {
+        auto member = GetCustomMemberBySocket(hdr->socket_handle);
+        if (member) {
+            JoinErrorHandle(msg, 100, hdr->socket_handle);
+            return;
+        }
+    }
     {
         cs::CMJoin* mutable_msg = (cs::CMJoin*)&msg;
         AdjustCMJoin(mutable_msg);