diff --git a/common.mjs b/common.mjs
index 3db03f1..c120597 100644
--- a/common.mjs
+++ b/common.mjs
@@ -5,6 +5,7 @@
 import fs from 'node:fs';
 import { readdir, readFile } from 'node:fs/promises';
 import { resolve } from 'node:path';
+import { Buffer } from 'node:buffer';
 import md5 from 'md5';
 
 class Common {
@@ -209,7 +210,7 @@ class Common {
     }
 
     byteSize(str) {
-        return new Blob([str]).size;
+        return Buffer.byteLength(str, 'utf8');
     }
 
 }