diff --git a/src/example/note/entity.py b/src/example/note/entity.py
index a50826e..08f4187 100644
--- a/src/example/note/entity.py
+++ b/src/example/note/entity.py
@@ -3,7 +3,7 @@
 from dataclasses import dataclass
 
 
-@dataclass(frozen=True)
+@dataclass(frozen=True, slots=True)
 class Note:
     id: int
     title: str