diff --git a/packages/frontend/src/scripts/nyaize.ts b/packages/frontend/src/scripts/nyaize.ts
index 62833b4de3..8b905ce156 100644
--- a/packages/frontend/src/scripts/nyaize.ts
+++ b/packages/frontend/src/scripts/nyaize.ts
@@ -3,14 +3,32 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-const enRegex1 = /(?<=n)a/gi;
-const enRegex2 = /(?<=morn)ing/gi;
-const enRegex3 = /(?<=every)one/gi;
-const koRegex1 = /[나-낳]/g;
-const koRegex2 = /(다$)|(다(?=\.))|(다(?= ))|(다(?=!))|(다(?=\?))/gm;
-const koRegex3 = /(야(?=\?))|(야$)|(야(?= ))/gm;
+let enRegex1: RegExp;
+let enRegex2: RegExp;
+let enRegex3: RegExp;
+let koRegex1: RegExp;
+let koRegex2: RegExp;
+let koRegex3: RegExp;
+let fallback: boolean = true;
 
-export function nyaize(text: string): string {
+try {
+	enRegex1 = new RegExp('(?<=n)a', 'gi');
+	enRegex2 = new RegExp('(?<=morn)ing', 'gi');
+	enRegex3 = new RegExp('(?<=every)one', 'gi');
+	koRegex1 = new RegExp('[나-낳]', 'g');
+	koRegex2 = new RegExp('(다$)|(다(?= ))|(다(?=!))|(다(?=\\?))|(다(?=\\.))', 'gm');
+	koRegex3 = new RegExp('(야$)|(야(?= ))|(야(?=!))|(야(?=\\?))|(야(?=\\.))', 'gm');
+	fallback = false;
+} catch {
+	enRegex1 = new RegExp('na', 'gi');
+	enRegex2 = new RegExp('morning', 'gi');
+	enRegex3 = new RegExp('everyone', 'gi');
+	koRegex1 = new RegExp('[나-낳]', 'g');
+	koRegex2 = new RegExp('다$', 'gm');
+	koRegex3 = new RegExp('야$', 'gm');
+}
+
+function convertNormal(text: string): string {
 	return text
 		// ja-JP
 		.replaceAll('な', 'にゃ').replaceAll('ナ', 'ニャ').replaceAll('ﾅ', 'ﾆｬ')
@@ -25,3 +43,23 @@ export function nyaize(text: string): string {
 		.replace(koRegex2, '다냥')
 		.replace(koRegex3, '냥');
 }
+
+function convertFallback(text: string): string {
+	return text
+		// ja-JP
+		.replaceAll('な', 'にゃ').replaceAll('ナ', 'ニャ').replaceAll('ﾅ', 'ﾆｬ')
+		// en-US
+		.replace(enRegex1, x => x === 'NA' ? 'NYA' : 'nya')
+		.replace(enRegex2, x => x === 'MORNING' ? 'MORNYAN' : 'mornyan')
+		.replace(enRegex3, x => x === 'EVERYONE' ? 'EVERYNYAN' : 'everynyan')
+		// ko-KR
+		.replace(koRegex1, match => String.fromCharCode(
+			match.charCodeAt(0)! + '냐'.charCodeAt(0) - '나'.charCodeAt(0),
+		))
+		.replace(koRegex2, '다냥').replaceAll('다 ', '다냥 ').replaceAll('다!', '다냥!').replaceAll('다?', '다냥?').replaceAll('다.', '다냥.')
+		.replace(koRegex3, '냥').replaceAll('야 ', '냥 ').replaceAll('야!', '냥!').replaceAll('야?', '냥?').replaceAll('야.', '냥.');
+}
+
+export function nyaize(text: string): string {
+	return !fallback ? convertNormal(text) : convertFallback(text);
+}
diff --git a/packages/frontend/src/workers/test-webgl2.ts b/packages/frontend/src/workers/test-webgl2.ts
index 8f57e5039b..1f3f640e6b 100644
--- a/packages/frontend/src/workers/test-webgl2.ts
+++ b/packages/frontend/src/workers/test-webgl2.ts
@@ -3,9 +3,9 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-const canvas = globalThis.OffscreenCanvas && new OffscreenCanvas(1, 1);
-// 環境によってはOffscreenCanvasが存在しないため
-// eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
+const canvas = typeof OffscreenCanvas !== 'undefined'
+	? new OffscreenCanvas(1, 1)
+	: undefined;
 const gl = canvas?.getContext('webgl2');
 if (gl) {
 	postMessage({ result: true });