diff --git a/core/config.class.inc.php b/core/config.class.inc.php
index 3622c41930..1aafd90d08 100644
--- a/core/config.class.inc.php
+++ b/core/config.class.inc.php
@@ -2856,20 +2856,8 @@ class Config
 						}
 					}
 				}
-				if (isset($aModuleInfo['installer']))
-				{
-					$sModuleInstallerClass = $aModuleInfo['installer'];
-					if (!class_exists($sModuleInstallerClass))
-					{
-						throw new Exception("Wrong installer class: '$sModuleInstallerClass' is not a PHP class - Module: ".$aModuleInfo['label']);
-					}
-					if (!is_subclass_of($sModuleInstallerClass, 'ModuleInstallerAPI'))
-					{
-						throw new Exception("Wrong installer class: '$sModuleInstallerClass' is not derived from 'ModuleInstallerAPI' - Module: ".$aModuleInfo['label']);
-					}
-					$aCallSpec = array($sModuleInstallerClass, 'BeforeWritingConfig');
-					call_user_func_array($aCallSpec, array($this));
-				}
+
+				ModuleDiscoveryService::GetInstance()->CallInstallerBeforeWritingConfigMethod($this, $aModuleInfo);
 			}
 		}
 		$this->SetAddOns($aAddOns);
diff --git a/setup/modulediscovery/ModuleDiscoveryService.php b/setup/modulediscovery/ModuleDiscoveryService.php
index 1e8263de84..9f37adca4f 100644
--- a/setup/modulediscovery/ModuleDiscoveryService.php
+++ b/setup/modulediscovery/ModuleDiscoveryService.php
@@ -60,6 +60,8 @@ class ModuleDiscoveryService {
 			{
 				throw new ModuleDiscoveryServiceException("Eval of $sModuleFilePath did  not return the expected information...");
 			}
+
+			$this->AddModuleFilePath($aModuleInfo);
 		}
 		catch(ModuleDiscoveryServiceException $e)
 		{
@@ -79,6 +81,20 @@ class ModuleDiscoveryService {
 		return $aModuleInfo;
 	}
 
+	/**
+	 * N°4789 - Parse datamodel module.xxx.php files instead of interpreting them
+	 * additional path added to handle ModuleInstallerAPI declaration during setup only
+	 * @param array &$aModuleInfo
+	 *
+	 * @return void
+	 */
+	private function AddModuleFilePath(array &$aModuleInfo)
+	{
+		if (count($aModuleInfo)==3) {
+			$aModuleInfo[2]['module_file_path'] = $aModuleInfo[0];
+		}
+	}
+
 	/**
 	 * @param string $sPhpContent
 	 *
@@ -112,6 +128,7 @@ class ModuleDiscoveryService {
 				if ($oNode instanceof \PhpParser\Node\Stmt\Expression) {
 					$aModuleConfig = $this->ParseCallToAddModuleAndReturnModuleConfiguration($sModuleFilePath, $oNode);
 					if (! is_null($aModuleConfig)){
+						$this->AddModuleFilePath($aModuleConfig);
 						return $aModuleConfig;
 					}
 				}
@@ -119,6 +136,7 @@ class ModuleDiscoveryService {
 				if ($oNode instanceof PhpParser\Node\Stmt\If_) {
 					$aModuleConfig = $this->BrowseIfStructure($sModuleFilePath, $oNode);
 					if (! is_null($aModuleConfig)){
+						$this->AddModuleFilePath($aModuleConfig);
 						return $aModuleConfig;
 					}
 				}
@@ -442,6 +460,37 @@ PHP;
 
 		return (bool) $method->invokeArgs(null, $aArgs);
 	}
+
+	/**
+	 *
+	 * @param \Config $oConfig
+	 * @param array $aModuleInfo
+	 *
+	 * @return void
+	 * @throws \ModuleDiscoveryServiceException
+	 */
+	public function CallInstallerBeforeWritingConfigMethod(Config $oConfig, array $aModuleInfo)
+	{
+		if (isset($aModuleInfo['installer']))
+		{
+			$sModuleInstallerClass = $aModuleInfo['installer'];
+			if (!class_exists($sModuleInstallerClass)) {
+				$sModuleFilePath = $aModuleInfo['module_file_path'];
+				$this->ReadModuleFileConfigurationLegacy($sModuleFilePath);
+			}
+
+			if (!class_exists($sModuleInstallerClass))
+			{
+				throw new Exception("Wrong installer class: '$sModuleInstallerClass' is not a PHP class - Module: ".$aModuleInfo['label']);
+			}
+			if (!is_subclass_of($sModuleInstallerClass, 'ModuleInstallerAPI'))
+			{
+				throw new Exception("Wrong installer class: '$sModuleInstallerClass' is not derived from 'ModuleInstallerAPI' - Module: ".$aModuleInfo['label']);
+			}
+			$aCallSpec = array($sModuleInstallerClass, 'BeforeWritingConfig');
+			call_user_func_array($aCallSpec, array($oConfig));
+		}
+	}
 }
 
 class ModuleDiscoveryServiceException extends Exception
diff --git a/tests/php-unit-tests/unitary-tests/setup/modulediscovery/ModuleDiscoveryServiceTest.php b/tests/php-unit-tests/unitary-tests/setup/modulediscovery/ModuleDiscoveryServiceTest.php
index 4044e12206..e68b3cbf86 100644
--- a/tests/php-unit-tests/unitary-tests/setup/modulediscovery/ModuleDiscoveryServiceTest.php
+++ b/tests/php-unit-tests/unitary-tests/setup/modulediscovery/ModuleDiscoveryServiceTest.php
@@ -108,19 +108,19 @@ class ModuleDiscoveryServiceTest extends ItopDataTestCase
 		return [
 			"simple call to SetupInfo::ModuleIsSelected SELECTED" => [
 				"expr" => $sSimpleCallToModuleIsSelected,
-				"expected" => true
+				"expected" => true,
 			],
 			"simple call to SetupInfo::ModuleIsSelected NOT SELECTED" => [
 				"expr" => $sSimpleCallToModuleIsSelected2,
-				"expected" => false
+				"expected" => false,
 			],
 			"call to SetupInfo::ModuleIsSelected + OR => SELECTED" => [
 				"expr" => $sCallToModuleIsSelectedCombinedWithAndOperator,
-				"expected" => true
+				"expected" => true,
 			],
 			"simple call to SetupInfo::ModuleIsSelected + OR => NOT SELECTED" => [
 				"expr" => $sCallToModuleIsSelectedCombinedWithAndOperator2,
-				"expected" => false
+				"expected" => false,
 			],
 		];
 	}
@@ -152,12 +152,11 @@ PHP;
 		$this->sTempModuleFilePath = tempnam(__DIR__, "test");
 		file_put_contents($this->sTempModuleFilePath, $sPHpCode);
 		try {
-			return $this->InvokeNonPublicMethod(ModuleDiscoveryService::class, "ReadModuleFileConfiguration", ModuleDiscoveryService::GetInstance(), [$this->sTempModuleFilePath]);
+			return ModuleDiscoveryService::GetInstance()->ReadModuleFileConfiguration($this->sTempModuleFilePath);
 		}
 		finally {
 			@unlink($this->sTempModuleFilePath);
 		}
-
 	}
 
 	public function testReadModuleFileConfigurationCheckBasicStatementWithoutIf()
@@ -169,7 +168,7 @@ SetupWebPage::AddModule("a", "noif", ["c" => "d"]);
 \$b=2;
 PHP;
 		$val = $this->CallReadModuleFileConfiguration($sPHP);
-		$this->assertEquals([$this->sTempModuleFilePath, "noif", ["c" => "d"]], $val);
+		$this->assertEquals([$this->sTempModuleFilePath, "noif", ["c" => "d", 'module_file_path' => $this->sTempModuleFilePath]], $val);
 	}
 
 	public function testReadModuleFileConfigurationCheckBasicStatement_IfConditionVerified()
@@ -190,7 +189,7 @@ SetupWebPage::AddModule("a", "outsideif", ["c" => "d"]);
 \$b=2;
 PHP;
 		$val = $this->CallReadModuleFileConfiguration($sPHP);
-		$this->assertEquals([$this->sTempModuleFilePath, "if", ["c" => "d"]], $val);
+		$this->assertEquals([$this->sTempModuleFilePath, "if", ["c" => "d", 'module_file_path' => $this->sTempModuleFilePath]], $val);
 	}
 
 	public function testReadModuleFileConfigurationCheckBasicStatement_IfNoConditionVerifiedAndNoElse()
@@ -209,7 +208,7 @@ SetupWebPage::AddModule("a", "outsideif", ["c" => "d"]);
 \$b=2;
 PHP;
 		$val = $this->CallReadModuleFileConfiguration($sPHP);
-		$this->assertEquals([$this->sTempModuleFilePath, "outsideif", ["c" => "d"]], $val);
+		$this->assertEquals([$this->sTempModuleFilePath, "outsideif", ["c" => "d", 'module_file_path' => $this->sTempModuleFilePath]], $val);
 	}
 
 	public function testReadModuleFileConfigurationCheckBasicStatement_ElseApplied()
@@ -230,7 +229,7 @@ SetupWebPage::AddModule("a", "outsideif", ["c" => "d"]);
 \$b=2;
 PHP;
 		$val = $this->CallReadModuleFileConfiguration($sPHP);
-		$this->assertEquals([$this->sTempModuleFilePath, "else", ["c" => "d"]], $val);
+		$this->assertEquals([$this->sTempModuleFilePath, "else", ["c" => "d", 'module_file_path' => $this->sTempModuleFilePath]], $val);
 	}
 
 	public function testReadModuleFileConfigurationCheckBasicStatement_FirstElseIfApplied()
@@ -251,7 +250,7 @@ SetupWebPage::AddModule("a", "outsideif", ["c" => "d"]);
 \$b=2;
 PHP;
 		$val = $this->CallReadModuleFileConfiguration($sPHP);
-		$this->assertEquals([$this->sTempModuleFilePath, "elseif1", ["c" => "d"]], $val);
+		$this->assertEquals([$this->sTempModuleFilePath, "elseif1", ["c" => "d", 'module_file_path' => $this->sTempModuleFilePath]], $val);
 	}
 
 	public function testReadModuleFileConfigurationCheckBasicStatement_LastElseIfApplied()
@@ -272,7 +271,7 @@ SetupWebPage::AddModule("a", "outsideif", ["c" => "d"]);
 \$b=2;
 PHP;
 		$val = $this->CallReadModuleFileConfiguration($sPHP);
-		$this->assertEquals([$this->sTempModuleFilePath, "elseif2", ["c" => "d"]], $val);
+		$this->assertEquals([$this->sTempModuleFilePath, "elseif2", ["c" => "d", 'module_file_path' => $this->sTempModuleFilePath]], $val);
 	}
 
 	public static function EvaluateExpressionBooleanProvider() {
@@ -286,85 +285,85 @@ PHP;
 		return [
 			"true" => [
 				"code" => str_replace("COND", "true", $sTruePHP),
-				"bool_expected" => true
+				"bool_expected" => true,
 
 			],
 			"false" => [
 				"code" => str_replace("COND", "false", $sTruePHP),
-				"bool_expected" => false
+				"bool_expected" => false,
 
 			],
 			"not ok" => [
 				"code" => str_replace("COND", "! false", $sTruePHP),
-				"bool_expected" => true
+				"bool_expected" => true,
 
 			],
 			"not ko" => [
 				"code" => str_replace("COND", "! (true)", $sTruePHP),
-				"bool_expected" => false
+				"bool_expected" => false,
 
 			],
 			"AND ko" => [
 				"code" => str_replace("COND", "true && false", $sTruePHP),
-				"bool_expected" => false
+				"bool_expected" => false,
 
 			],
 			"AND ok1" => [
 				"code" => str_replace("COND", "true && true", $sTruePHP),
-				"bool_expected" => true
+				"bool_expected" => true,
 
 			],
 			"AND ko2" => [
 				"code" => str_replace("COND", "true && true && false", $sTruePHP),
-				"bool_expected" => false
+				"bool_expected" => false,
 
 			],
 			"OR ko" => [
 				"code" => str_replace("COND", "false || false", $sTruePHP),
-				"bool_expected" => false
+				"bool_expected" => false,
 
 			],
 			"OR ok" => [
 				"code" => str_replace("COND", "false ||true", $sTruePHP),
-				"bool_expected" => true
+				"bool_expected" => true,
 
 			],
 			"OR ok2" => [
 				"code" => str_replace("COND", "false ||false||true", $sTruePHP),
-				"bool_expected" => true
+				"bool_expected" => true,
 
 			],
 			"function_exists('ldap_connect')" => [
 				"code" => str_replace("COND", "function_exists('ldap_connect')", $sTruePHP),
-				"bool_expected" => function_exists('ldap_connect')
+				"bool_expected" => function_exists('ldap_connect'),
 
 			],
 			"function_exists('gabuzomeushouldnotexist')" => [
 				"code" => str_replace("COND", "function_exists('gabuzomeushouldnotexist')", $sTruePHP),
-				"bool_expected" => function_exists('gabuzomeushouldnotexist')
+				"bool_expected" => function_exists('gabuzomeushouldnotexist'),
 
 			],
 			"1 > 2" => [
 				"code" => str_replace("COND", "1 > 2", $sTruePHP),
-				"bool_expected" => false
+				"bool_expected" => false,
 
 			],
 			"1 == 1" => [
 				"code" => str_replace("COND", "1 == 1", $sTruePHP),
-				"bool_expected" => true
+				"bool_expected" => true,
 
 			],
 			"1 < 2" => [
 				"code" => str_replace("COND", "1 < 2", $sTruePHP),
-				"bool_expected" => true
+				"bool_expected" => true,
 			],
 			"PHP_VERSION_ID == PHP_VERSION_ID" => [
 				"code" => str_replace("COND", "PHP_VERSION_ID == PHP_VERSION_ID", $sTruePHP),
-				"bool_expected" => true
+				"bool_expected" => true,
 			],
 			"PHP_VERSION_ID != PHP_VERSION_ID" => [
 				"code" => str_replace("COND", "PHP_VERSION_ID != PHP_VERSION_ID", $sTruePHP),
-				"bool_expected" => false
+				"bool_expected" => false,
 			],
 		];
 	}
@@ -380,4 +379,27 @@ PHP;
 		$val = $this->InvokeNonPublicMethod(ModuleDiscoveryService::class, "EvaluateBooleanExpression", ModuleDiscoveryService::GetInstance(), [$oExpr->cond]);
 		$this->assertEquals($bExpected, $val);
 	}
+
+	public function testCallDeclaredInstaller()
+	{
+		$sModuleInstallerClass = "TicketsInstaller" . uniqid();
+		$sPHpCode = file_get_contents(__DIR__.'/resources/module.itop-tickets.php');
+		$sPHpCode = str_replace("TicketsInstaller", $sModuleInstallerClass, $sPHpCode);
+		$this->sTempModuleFilePath = tempnam(__DIR__, "test");
+		file_put_contents($this->sTempModuleFilePath, $sPHpCode);
+		var_dump($sPHpCode);
+
+		try {
+			$this->assertFalse(class_exists($sModuleInstallerClass));
+			$aModuleInfo = ModuleDiscoveryService::GetInstance()->ReadModuleFileConfiguration($this->sTempModuleFilePath);
+			$this->assertFalse(class_exists($sModuleInstallerClass));
+
+			ModuleDiscoveryService::GetInstance()->CallInstallerBeforeWritingConfigMethod(\MetaModel::GetConfig(), $aModuleInfo[2]);
+		}
+		finally {
+			@unlink($this->sTempModuleFilePath);
+		}
+
+		$this->assertTrue(class_exists($sModuleInstallerClass));
+	}
 }
\ No newline at end of file
diff --git a/tests/php-unit-tests/unitary-tests/setup/modulediscovery/resources/module.itop-tickets.php b/tests/php-unit-tests/unitary-tests/setup/modulediscovery/resources/module.itop-tickets.php
new file mode 100644
index 0000000000..f46fc1f231
--- /dev/null
+++ b/tests/php-unit-tests/unitary-tests/setup/modulediscovery/resources/module.itop-tickets.php
@@ -0,0 +1,107 @@
+<?php
+
+
+SetupWebPage::AddModule(
+	__FILE__,
+	'itop-tickets/3.3.0',
+	array(
+		// Identification
+		//
+		'label' => 'Tickets Management',
+		'category' => 'business',
+
+		// Setup
+		//
+		'dependencies' => array(
+			'itop-structure/2.7.1',
+		),
+		'mandatory' => false,
+		'visible' => true,
+		'installer' => 'TicketsInstaller',
+
+		// Components
+		//
+		'datamodel' => array(
+			'main.itop-tickets.php',
+		),
+		'data.struct' => array(
+	//		'data.struct.ta-actions.xml',
+		),
+		'data.sample' => array(
+		),
+		
+		// Documentation
+		//
+		'doc.manual_setup'     => '',
+		'doc.more_information' => '',
+
+		// Default settings
+		//
+		'settings' => array(
+		),
+	)
+);
+
+// Module installation handler
+//
+class TicketsInstaller extends ModuleInstallerAPI
+{
+	public static function AfterDatabaseCreation(Config $oConfiguration, $sPreviousVersion, $sCurrentVersion)
+	{
+		// Delete all Triggers corresponding to a no more valid class
+		CMDBObject::SetTrackInfo('Uninstallation');
+		$oSearch = new DBObjectSearch('TriggerOnObject');
+		$oSet = new DBObjectSet($oSearch);
+		while($oTrigger = $oSet->Fetch())
+		{
+			try
+			{
+				if (!MetaModel::IsValidClass($oTrigger->Get('target_class')))
+				{
+					$oTrigger->DBDelete();
+				}
+			}
+			catch(Exception $e)
+			{
+				utils::EnrichRaisedException($oTrigger, $e);
+			}
+		}
+		// It's not very clear if it make sense to test a particular version,
+		// as the loading mechanism checks object existence using reconc_keys
+		// and do not recreate them, nor update existing.
+		// Without test, new entries added to the data files, would be automatically loaded
+		if (($sPreviousVersion === '') ||
+			(version_compare($sPreviousVersion, $sCurrentVersion, '<')
+				&& version_compare($sPreviousVersion, '3.0.0', '<'))) {
+			$oDataLoader = new XMLDataLoader();
+
+			CMDBObject::SetTrackInfo("Initialization TicketsInstaller");
+			$oMyChange = CMDBObject::GetCurrentChange();
+
+			$sLang = null;
+			// - Try to get app. language from configuration fil (app. upgrade)
+			$sConfigFileName = APPCONF.'production/'.ITOP_CONFIG_FILE;
+			if (file_exists($sConfigFileName)) {
+				$oFileConfig = new Config($sConfigFileName);
+				if (is_object($oFileConfig)) {
+					$sLang = str_replace(' ', '_', strtolower($oFileConfig->GetDefaultLanguage()));
+				}
+			}
+
+			// - I still no language, get the default one
+			if (null === $sLang) {
+				$sLang = str_replace(' ', '_', strtolower($oConfiguration->GetDefaultLanguage()));
+			}
+
+			$sFileName = dirname(__FILE__)."/data/{$sLang}.data.itop-tickets.xml";
+			SetupLog::Info("Searching file: $sFileName");
+			if (!file_exists($sFileName)) {
+				$sFileName = dirname(__FILE__)."/data/en_us.data.itop-tickets.xml";
+			}
+			SetupLog::Info("Loading file: $sFileName");
+			$oDataLoader->StartSession($oMyChange);
+			$oDataLoader->LoadFile($sFileName, false, true);
+			$oDataLoader->EndSession();
+		}
+	}
+}