diff --git a/src/server/api/endpoints/users/lists/update.ts b/src/server/api/endpoints/users/lists/update.ts
new file mode 100644
index 0000000000..b80d648122
--- /dev/null
+++ b/src/server/api/endpoints/users/lists/update.ts
@@ -0,0 +1,55 @@
+import $ from 'cafy'; import ID from '../../../../../misc/cafy-id';
+import UserList, { pack } from '../../../../../models/user-list';
+import { ILocalUser } from '../../../../../models/user';
+import getParams from '../../../get-params';
+
+export const meta = {
+	desc: {
+		'ja-JP': '指定したユーザーリストを更新します。',
+		'en-US': 'Update a user list'
+	},
+
+	requireCredential: true,
+
+	kind: 'account-write',
+
+	params: {
+		listId: $.type(ID).note({
+			desc: {
+				'ja-JP': '対象となるユーザーリストのID',
+				'en-US': 'ID of target user list'
+			}
+		}),
+		title: $.str.range(1, 100).note({
+			desc: {
+				'ja-JP': 'このユーザーリストの名前',
+				'en-US': 'name of this user list'
+			}
+		})
+	}
+};
+
+export default async (params: any, user: ILocalUser) => new Promise(async (res, rej) => {
+	const [ps, psErr] = getParams(meta, params);
+	if (psErr) throw psErr;
+
+	// Fetch the list
+	const userList = await UserList.findOne({
+		_id: ps.listId,
+		userId: user._id
+	});
+
+	if (userList == null) {
+		return rej('list not found');
+	}
+
+	// update
+	await UserList.update({ _id: userList._id }, {
+		$set: {
+			title: ps.title
+		}
+	});
+
+	// Response
+	res(await pack(userList._id));
+});