---
title: "Override service registration"
manual: "TYPO3 Explained"
version: "12.4"
permalink: "https://docs.typo3.org/permalink/t3coreapi:services-configuration-registration-changes@12.4"
source: "ApiOverview/Services/Configuration/RegistrationChanges.rst"
rendered: "2026-10-21T15:29:37+00:00"
---

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# Override service registration {#services-configuration-registration-changes}

The priority and other values of the original service registration can be
overridden in any extension's [`ext_localconf.php`](../../../ExtensionArchitecture/FileStructure/ExtLocalconf.md#file-extension-ext-localconf-php) file. Example:

**EXT:my_extension/ext_localconf.php**

```php
<?php

declare(strict_types=1);

defined('TYPO3') or die();

// Raise priority of service 'tx_example_sv1' to 110
$GLOBALS['TYPO3_CONF_VARS']['T3_SERVICES']['auth']['tx_example_sv1']['priority'] = 110;

// Disable service 'tx_example_sv1'
$GLOBALS['TYPO3_CONF_VARS']['T3_SERVICES']['auth']['tx_example_sv1']['enable'] = false;

```

The general syntax is:

```php
$GLOBALS['TYPO3_CONF_VARS']['T3_SERVICES'][service type][service key][option key] = value;
```

Registration options are described in more details in
[Implementing a service](https://docs.typo3.org/permalink/t3coreapi:services-developer-implementing@12.4).
Any of these options may be overridden using the above
syntax. However caution should be used depending on the options.
`className` should not be overridden in such a way.
Instead a new service should be implemented using an alternate
class.