diff --git a/src/installer-rp/pack.ts b/src/installer-rp/pack.ts
index 6ab5558..aeb3ebd 100644
--- a/src/installer-rp/pack.ts
+++ b/src/installer-rp/pack.ts
@@ -64,13 +64,19 @@ export async function buildResourcepackZip(opts: BuildResourcepackOptions): Prom
   } else {
     opts.log?.(t('log.packFormatFallback', { format: resolved.format, version: opts.mcVersion }))
   }
-  const mcmeta = {
-    pack: {
-      description: t('pack.description', { name: opts.packName }),
-      pack_format: resolved.format,
-      supported_formats: { min_inclusive: resolved.format, max_inclusive: resolved.format }
-    }
+  // pack_format > 64 (즉 1.21.9+) 부터는 supported_formats 가 폐기되고
+  // min_format / max_format 가 필수다. 그 이하는 종전대로 supported_formats 사용.
+  const packMeta: Record<string, unknown> = {
+    description: t('pack.description', { name: opts.packName }),
+    pack_format: resolved.format
   }
+  if (resolved.format > 64) {
+    packMeta.min_format = resolved.format
+    packMeta.max_format = resolved.format
+  } else {
+    packMeta.supported_formats = { min_inclusive: resolved.format, max_inclusive: resolved.format }
+  }
+  const mcmeta = { pack: packMeta }
   await fs.writeFile(path.join(root, 'pack.mcmeta'), JSON.stringify(mcmeta, null, 2) + '\n')
 
   // 2) 음악 파일 복사 + sounds.json 생성/병합