diff --git a/test/fixtures/custom-data-test.js b/test/fixtures/custom-data-test.js
deleted file mode 100644
index be2cd14c53..0000000000
--- a/test/fixtures/custom-data-test.js
+++ /dev/null
@@ -1,37 +0,0 @@
-/*
- * Copyright (C) 2023  Yomitan Authors
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
-import {test} from 'vitest';
-
-/**
- * @template [TCustomData=unknown]
- * @param {() => (TCustomData|Promise<TCustomData>)} createCustomData
- * @param {(data: TCustomData) => (void|Promise<void>)} [disposeCustomData]
- * @returns {import('vitest').TestAPI<{custom: {data: TCustomData}}>}
- */
-export function createCustomDataTest(createCustomData, disposeCustomData) {
-    return test.extend({
-        // eslint-disable-next-line no-empty-pattern
-        custom: async ({}, use) => {
-            const data = await createCustomData();
-            await use({data});
-            if (typeof disposeCustomData === 'function') {
-                disposeCustomData(data);
-            }
-        }
-    });
-}