diff --git a/implementations/javascript/packages/core/src/bytes.ts b/implementations/javascript/packages/core/src/bytes.ts
index ff711e0..6633f14 100644
--- a/implementations/javascript/packages/core/src/bytes.ts
+++ b/implementations/javascript/packages/core/src/bytes.ts
@@ -6,7 +6,7 @@ import type { Writer, PreserveWritable } from './writer';
 import { decodeBase64, encodeBase64 } from './base64';
 
 const textEncoder = new TextEncoder();
-const textDecoder = new TextDecoder();
+const textDecoder = new TextDecoder('utf-8', { fatal: true });
 
 export const IsPreservesBytes = Symbol.for('IsPreservesBytes');