# new_classes on PUT /client/v4/accounts/{}/workers/scripts/{} stops working

Calls to PUT /client/v4/accounts/{}/workers/scripts/{}, body parameter new_classes on Cloudflare stopped working on July 9, 2026.

- API: Cloudflare (api.cloudflare.com)
- Kind: Behaviour change
- Announced: July 9, 2026
- Takes effect: July 9, 2026
- Calls after that day: fail
- Calls it hits: `PUT /client/v4/accounts/{}/workers/scripts/{}`, `body parameter new_classes`
- Source: [Announcement](https://developers.cloudflare.com/changelog/post/2026-07-09-restrict-new-kv-backed-namespaces/)
- Page: https://www.okapi.bot/providers/cloudflare/breaking-changes/new-classes-on-put-client-v4-accounts-workers-scripts-stops-working/

## What to use instead

Create Durable Object classes with a new_sqlite_classes migration instead of new_classes.