---
format: "aidr-story-markdown/v1"
id: "93665dfbd055983cb09a185c90887d1653c36928bbf25fd9eb6f9e0810d24e07"
canonical_url: "https://aidr.today/93665dfb?lang=en"
title: "Anthropic's watermark rollout leaves a loophole on two older Claude models"
lang: "en"
requested_lang: "en"
available_langs: ["en","vi"]
translation_fallback: null
fallback_fields: []
published_at: "2026-10-31T19:20:55.000Z"
category: "Regulation"
topics: ["anthropic","regulation"]
source_urls: ["https://the-decoder.com/anthropics-watermark-rollout-leaves-a-loophole-on-two-older-claude-models/"]
summary: "Anthropic is expanding its text watermark to four more Claude models to meet the EU AI Act's December deadline. On the older models Claude Opus 4.6 and Sonnet 4.6, developers can bypass the watermark by tweaking a single sampling parameter. Anthropic addresses the loophole with just a compliance warning."
---

# Anthropic's watermark rollout leaves a loophole on two older Claude models

> [Open the canonical story](<https://aidr.today/93665dfb?lang=en>)

**Published:** 2026-10-31T19:20:55.000Z
**Category:** Regulation
**Topics:** anthropic, regulation

## Summary

Anthropic is expanding its text watermark to four more Claude models to meet the EU AI Act's December deadline\. On the older models Claude Opus 4\.6 and Sonnet 4\.6, developers can bypass the watermark by tweaking a single sampling parameter\. Anthropic addresses the loophole with just a compliance warning\.

## Sources

- [Story source](<https://the-decoder.com/anthropics-watermark-rollout-leaves-a-loophole-on-two-older-claude-models/>)