diff --git a/server/gameserver/mt/Map.cc b/server/gameserver/mt/Map.cc
index 63fb05e3..67351151 100644
--- a/server/gameserver/mt/Map.cc
+++ b/server/gameserver/mt/Map.cc
@@ -238,6 +238,22 @@ namespace mt
                     _world_objects.push_back(obj);
                 }
             }
+            {
+                auto group = root.At("group");
+                for (int i = 0; i < group->Size(); ++i) {
+                    auto group_obj = group->At(i);
+                    for (int ii = 0; ii < group_obj->Size(); ++ii) {
+                        std::vector<std::string> keys;
+                        group_obj->GetKeys(keys);
+                        for (auto key : keys) {
+                            int ikey = a8::XValue(key);
+                            if (_group_world_objects.find(ikey) != _group_world_objects.end()) {
+                                abort();
+                            }
+                        }
+                    }
+                }
+            }
         }
     }
 
diff --git a/server/gameserver/mt/Map.h b/server/gameserver/mt/Map.h
index 6fd48606..41cacf54 100644
--- a/server/gameserver/mt/Map.h
+++ b/server/gameserver/mt/Map.h
@@ -34,6 +34,7 @@ namespace mt
         std::map<int, int> car_num_limit_;
         std::vector<int> safearea_list;
         std::vector<std::shared_ptr<WorldObject>> _world_objects;
+        std::map<int, std::vector<std::shared_ptr<WorldObject>>> _group_world_objects;
         MapCollider* collider_info = nullptr;
 
         std::string RandTemplate() const;