diff --git a/src/components/gameMaster/mapEditor/Map.vue b/src/components/gameMaster/mapEditor/Map.vue
index 4e20c8b..3e6de50 100644
--- a/src/components/gameMaster/mapEditor/Map.vue
+++ b/src/components/gameMaster/mapEditor/Map.vue
@@ -32,7 +32,7 @@ let commandIndex = ref(0)
 
 let originTiles: string[][] = []
 let originEventTiles: MapEventTile[] = []
-let originObjects = ref<PlacedMapObjectT[]>(mapEditor.currentMap.value.placedMapObjects)
+let originObjects = ref<PlacedMapObjectT[]>(mapEditor.currentMap.value?.placedMapObjects ?? [])
 
 const { undo, redo, commit, pause, resume, canUndo, canRedo } = useRefHistory(originObjects, { deep: true, capacity: 9 })