---
title: "Breaking: #81735 - Get rid of sysext:sv"
manual: "TYPO3 Core Changelog"
version: "main"
permalink: "https://docs.typo3.org/permalink/changelog:changelog-breaking-81735-getridofsysextsv"
source: "Changelog/9.0/Breaking-81735-GetRidOfSysextsv.rst"
modified: "2026-09-14T09:47:36+00:00"
---

# Breaking: #81735 - Get rid of sysext:sv

See [forge#81735](https://forge.typo3.org/issues/81735)

## Description

The AuthenticationService has been moved into system extension `core`. Class aliases are in place and
will be removed with TYPO3 v10.

## Impact

The namespace of the classes `AbstractAuthenticationService` and `AuthenticationService` changed
from `\TYPO3\CMS\Sv` to `\TYPO3\CMS\Core\Authentication`.

## Affected Installations

All instances, that use or extend the mentioned classes.

## Migration

Use the new namespaces as mentioned above.

## Related

-   [Breaking: #81536 - Move ServicesListReport From Sv to Reports](https://docs.typo3.org/permalink/changelog:changelog-moveofserviceslistreportfromsvtoreports)

## More Information

-   [Service API](https://docs.typo3.org/m/typo3/reference-coreapi/main/en-us/ApiOverview/Services/Developer/ServiceApi.html#services-developer-service-api) in "TYPO3 Explained"