diff --git a/src/services/note/create.ts b/src/services/note/create.ts
index 84daa7dfe..20fa4a8d5 100644
--- a/src/services/note/create.ts
+++ b/src/services/note/create.ts
@@ -188,6 +188,11 @@ export default async (user: IUser, data: Option, silent = false) => new Promise<
 				data.visibleUsers.push(u);
 			}
 		}
+
+		// ダイレクト投稿でユーザーが指定されていなかったらreject
+		if (data.visibleUsers.length === 0) {
+			return rej('Target user is not specified');
+		}
 	}
 
 	const note = await insertNote(user, data, tags, emojis, mentionedUsers);