---
title: "Deprecation: #88569 - Locales::initialize() in favor of regular singleton instance"
manual: "TYPO3 Core Changelog"
version: "main"
permalink: "https://docs.typo3.org/permalink/changelog:deprecation-88569"
source: "Changelog/10.0/Deprecation-88569-LocalesinitializeInFavorOfRegularSingletonInstance.rst"
typo3-version: "10.0"
typo3-major: 10
type: "deprecation"
issue: 88569
forge: "https://forge.typo3.org/issues/88569"
tags: ["PHP-API", "FullyScanned"]
rendered: "2026-09-18T17:00:34+00:00"
---

# Deprecation: #88569 - Locales::initialize() in favor of regular singleton instance {#deprecation-88569}

See [forge#88569](https://forge.typo3.org/issues/88569)

## Description {#description}

The method `TYPO3\CMS\Core\Localization\Locales::initialize()` has been marked as deprecated.
It was a workaround to re-initialize the Singleton Instance of the PHP class `Locales` for user-defined locales, which were
loaded by an extensions' `ext_localconf.php`.

`Locales` is now initialized only when needed, and not during the early bootstrap process,
making this functionality obsolete, as this is taken care of within the regular constructor.

## Impact {#impact}

Calling `TYPO3\CMS\Core\Localization\Locales::initialize()` will trigger a PHP `E_USER_DEPRECATED` error.

## Affected Installations {#affected-installations}

Any TYPO3 installation with a third-party extension calling `Locales::initialize()` directly.

## Migration {#migration}

Replace the function call by a regular `GeneralUtility::makeInstance(Locales::class);`
or use Dependency Injection (Constructor Injection or ObjectManager) to fetch an instance of
the `Locales` class.