diff --git a/packages/frontend/src/components/global/RouterView.vue b/packages/frontend/src/components/global/RouterView.vue
index aeb87e659b..f67700c2e8 100644
--- a/packages/frontend/src/components/global/RouterView.vue
+++ b/packages/frontend/src/components/global/RouterView.vue
@@ -20,7 +20,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 <script lang="ts" setup>
 import { inject, onBeforeUnmount, provide, ref, shallowRef, computed, nextTick } from 'vue';
-import { IRouter, Resolved, RouteDef } from '@/nirax.js';
+import { IRouter, Resolved } from '@/nirax.js';
 import { defaultStore } from '@/store.js';
 import { globalEvents } from '@/events.js';
 import MkLoadingPage from '@/pages/_loading_.vue';
@@ -76,7 +76,7 @@ router.addListener('change', onChange);
 
 /**
  * キャッシュクリアが有効になったら、全キャッシュをクリアする
- * 
+ *
  * keepAlive側にwatcherがあるのですぐ消えるとはおもうけど、念のためページ遷移完了まではキャッシュを無効化しておく。
  * キャッシュ有効時向けにexcludeを使いたい場合は、pageCacheControllerに並列に突っ込むのではなく、下に追記すること
  */
diff --git a/packages/frontend/src/scripts/code-highlighter.ts b/packages/frontend/src/scripts/code-highlighter.ts
index b11dfed41a..03bb43609a 100644
--- a/packages/frontend/src/scripts/code-highlighter.ts
+++ b/packages/frontend/src/scripts/code-highlighter.ts
@@ -18,9 +18,9 @@ export async function getTheme(mode: 'light' | 'dark', getName = false): Promise
 
 	if (theme.base) {
 		const base = [lightTheme, darkTheme].find(x => x.id === theme.base);
-		if (base && base.codeHighlighter) theme.codeHighlighter = Object.assign({}, base.codeHighlighter, theme.codeHighlighter);
+		if (base?.codeHighlighter) theme.codeHighlighter = { ...base.codeHighlighter, ...theme.codeHighlighter };
 	}
-	
+
 	if (theme.codeHighlighter) {
 		let _res: ThemeRegistration = {};
 		if (theme.codeHighlighter.base === '_none_') {
@@ -55,7 +55,7 @@ export async function getHighlighter(): Promise<Highlighter> {
 
 export async function initHighlighter() {
 	const aiScriptGrammar = await import('aiscript-vscode/aiscript/syntaxes/aiscript.tmLanguage.json');
-	
+
 	await loadWasm(import('shiki/onig.wasm?init'));
 
 	// テーマの重複を消す