---
title: "Deprecation: #85462 - Signal 'tablesDefinitionIsBeingBuilt'"
manual: "TYPO3 Core Changelog"
version: "main"
permalink: "https://docs.typo3.org/permalink/changelog:deprecation-85462"
source: "Changelog/9.4/Deprecation-85462-SignalTablesDefinitionIsBeingBuilt.rst"
modified: "2026-09-14T09:47:36+00:00"
---

# Deprecation: #85462 - Signal 'tablesDefinitionIsBeingBuilt'

See [forge#85462](https://forge.typo3.org/issues/85462)

## Description

The usage of signal `tablesDefinitionIsBeingBuilt` of class
`\TYPO3\CMS\Extensionmanager\Utility\InstallUtility`
has been marked as deprecated and will be removed in TYPO3 v10.

The signal is a duplication of `tablesDefinitionIsBeingBuilt` of class
`\TYPO3\CMS\Install\Service\SqlExpectedSchemaService` that is now also emitted during
extension installation.

## Impact

Slots of this signal will get executed in TYPO3 v9 but will be abandoned with TYPO3 v10. If a slot provides
SQL definitions a PHP `E_USER_DEPRECATED` error is triggered.

## Affected Installations

Extensions that register slots for the signal `tablesDefinitionIsBeingBuilt` of class
`\TYPO3\CMS\Extensionmanager\Utility\InstallUtility`.

## Migration

Extensions should use the signal `tablesDefinitionIsBeingBuilt` of class
`\TYPO3\CMS\Install\Service\SqlExpectedSchemaService` instead which is now emitted during an
extension installation.