diff --git a/packages/client/src/scripts/check-word-mute.ts b/packages/client/src/scripts/check-word-mute.ts
index 7a39950c..acdaf438 100644
--- a/packages/client/src/scripts/check-word-mute.ts
+++ b/packages/client/src/scripts/check-word-mute.ts
@@ -12,11 +12,15 @@ function checkLangMute(
 	note: firefish.entities.Note,
 	mutedLangs: Array<string | string[]>,
 ): Muted {
-	const mutedLangList = new Set(
-		mutedLangs.reduce((arr, x) => [...arr, ...(Array.isArray(x) ? x : [x])]),
-	);
-	if (mutedLangList.has((note.lang?.[0]?.lang || "").split("-")[0])) {
-		return { muted: true, matched: [note.lang?.[0]?.lang] };
+	const mutedLangList = new Set(mutedLangs.flatMap((e) => e));
+	// handle subtags
+	// e.g. if lang = "zh-hant-tw", check ["zh", "zh-hant", "zh-hant-tw"]
+	const langChunks: string[] = (note.lang || "").split("-");
+	for (let i = 0; i < langChunks.length; i++) {
+		const lang = langChunks.slice(0, i + 1).join("-");
+		if (mutedLangList.has(lang)) {
+			return { muted: true, matched: [lang] };
+		}
 	}
 	return NotMuted;
 }