diff --git a/packages/backend/src/core/entities/UserEntityService.ts b/packages/backend/src/core/entities/UserEntityService.ts
index 4e2f0317ddee2dd65410cb6efdae5b7f1db4ac4d..a7f62c05f79af1a708348ff6c051c9b7b3c32bef 100644
--- a/packages/backend/src/core/entities/UserEntityService.ts
+++ b/packages/backend/src/core/entities/UserEntityService.ts
@@ -412,7 +412,7 @@ export class UserEntityService implements OnModuleInit {
 					userId: meId,
 					targetUserId: user.id,
 				}).then(row => row?.memo ?? null),
-				moderationNote: iAmModerator ? (profile!.moderationNote ?? '') : null,
+				moderationNote: iAmModerator ? (profile!.moderationNote ?? '') : undefined,
 			} : {}),
 
 			...(opts.detail && isMe ? {
diff --git a/packages/backend/test/e2e/users.ts b/packages/backend/test/e2e/users.ts
index 917b9fbc94be0b21745f8244709138783dfa1e68..c1a57f102faf350f0dc02319bfe0c5357e26f5fb 100644
--- a/packages/backend/test/e2e/users.ts
+++ b/packages/backend/test/e2e/users.ts
@@ -112,7 +112,6 @@ describe('ユーザー', () => {
 			securityKeys: user.securityKeys,
 			roles: user.roles,
 			memo: user.memo,
-			moderationNote: user.moderationNote,
 		});
 	};