diff --git a/setup/unattended-install/InstallationFileService.php b/setup/unattended-install/InstallationFileService.php
index 301fd8ba2..77dad4cbd 100644
--- a/setup/unattended-install/InstallationFileService.php
+++ b/setup/unattended-install/InstallationFileService.php
@@ -21,6 +21,7 @@ class InstallationFileService {
 	private $sInstallationPath;
 	private $aSelectedModules;
 	private $aSelectedExtensions;
+	private $aAfterComputationSelectedExtensions;
 	private $aUnSelectedModules;
 	private $aAutoSelectModules;
 	private $bInstallationOptionalChoicesChecked;
@@ -37,6 +38,7 @@ class InstallationFileService {
 		$this->aUnSelectedModules = [];
 		$this->sTargetEnvironment = $sTargetEnvironment;
 		$this->aSelectedExtensions = $aSelectedExtensions;
+		$this->aAfterComputationSelectedExtensions = (count($aSelectedExtensions)==0) ? [] : $aSelectedExtensions;
 		$this->bInstallationOptionalChoicesChecked = $bInstallationOptionalChoicesChecked;
 	}
 
@@ -51,6 +53,10 @@ class InstallationFileService {
 		$this->oProductionEnv = $oProductionEnv;
 	}
 
+	public function GetAfterComputationSelectedExtensions(): array {
+		return $this->aAfterComputationSelectedExtensions;
+	}
+
 	public function GetAutoSelectModules(): array {
 		return $this->aAutoSelectModules;
 	}
@@ -146,10 +152,13 @@ class InstallationFileService {
 		$sMandatory = $aChoiceInfo["mandatory"] ?? "false";
 
 		$aCurrentModules = $aChoiceInfo["modules"] ?? [];
+		$sExtensionCode = $aChoiceInfo["extension_code"] ?? null;
 		if (0 === count($this->aSelectedExtensions)){
 			$bSelected = $bAllChecked || $sDefault === "true" || $sMandatory === "true";
+			if ($bSelected){
+				$this->aAfterComputationSelectedExtensions[]= $sExtensionCode;
+			}
 		} else {
-			$sExtensionCode = $aChoiceInfo["extension_code"] ?? null;
 			$bSelected = $sMandatory === "true" ||
 				(null !== $sExtensionCode && in_array($sExtensionCode, $this->aSelectedExtensions));
 		}
diff --git a/setup/unattended-install/unattended-install.php b/setup/unattended-install/unattended-install.php
index 10dc03fc0..5a630381d 100644
--- a/setup/unattended-install/unattended-install.php
+++ b/setup/unattended-install/unattended-install.php
@@ -63,7 +63,8 @@ if (! is_null($sInstallationXmlPath) && is_file($sInstallationXmlPath)) {
 	$sInstallationBaseName = basename($sInstallationXmlPath);
 
 	$aSelectedExtensionsFromXmlSetup = $oParams->Get('selected_extensions', []);
-	if (count($aSelectedExtensionsFromXmlSetup) !== 0) {
+	$bInstallationChoicesProvided = count($aSelectedExtensionsFromXmlSetup) !== 0;
+	if ($bInstallationChoicesProvided) {
 		$sMsg = "Modules to install computed based on $sInstallationBaseName file and installation choices (listed in section `selected_extensions` of $sXmlSetupBaseName file)";
 		echo "$sMsg:\n".implode(',', $aSelectedExtensionsFromXmlSetup)."\n\n";
 		SetupLog::Info($sMsg, null, $aSelectedExtensionsFromXmlSetup);
@@ -75,11 +76,21 @@ if (! is_null($sInstallationXmlPath) && is_file($sInstallationXmlPath)) {
 
 	$oInstallationFileService = new InstallationFileService($sInstallationXmlPath, $sTargetEnvironment, $aSelectedExtensionsFromXmlSetup);
 	$oInstallationFileService->Init();
+
+	$aComputedExtensions = $oInstallationFileService->GetAfterComputationSelectedExtensions();
+	if (! $bInstallationChoicesProvided) {
+		$sMsg = "Computed installation choices";
+		echo "$sMsg:\n".implode(',', $aComputedExtensions)."\n\n";
+		SetupLog::Info($sMsg, null, $aComputedExtensions);
+	}
+	$aSelectedExtensions = array_keys($aComputedExtensions);
+	$oParams->Set('selected_extensions', $aSelectedExtensions);
+
 	$aComputedModules = $oInstallationFileService->GetSelectedModules();
 	$aSelectedModules = array_keys($aComputedModules);
 	$oParams->Set('selected_modules', $aSelectedModules);
 
-	$sMsg = "Modules to install computed";
+	$sMsg = "Computed modules to install";
 } else {
 	$aSelectedModules = $oParams->Get('selected_modules', []);
 	$sMsg = "Modules to install listed in $sXmlSetupBaseName (selected_modules section)";
diff --git a/tests/php-unit-tests/unitary-tests/setup/unattended-install/InstallationFileServiceTest.php b/tests/php-unit-tests/unitary-tests/setup/unattended-install/InstallationFileServiceTest.php
index 272e913e2..9aefa4237 100644
--- a/tests/php-unit-tests/unitary-tests/setup/unattended-install/InstallationFileServiceTest.php
+++ b/tests/php-unit-tests/unitary-tests/setup/unattended-install/InstallationFileServiceTest.php
@@ -195,12 +195,34 @@ class InstallationFileServiceTest extends ItopTestCase {
 		sort($aExpectedUnselectedModules);
 		sort($aUnselectedModules);
 		$this->assertEquals($aExpectedUnselectedModules, $aUnselectedModules);
+
+		$aGetAfterComputationSelectedExtensions = $oInstallationFileService->GetAfterComputationSelectedExtensions();
+		sort($aGetAfterComputationSelectedExtensions);
+		$aExpectedExtensions = [
+			'itop-change-mgmt-simple',
+		    'itop-config-mgmt-core',
+		    'itop-config-mgmt-datacenter',
+		    'itop-config-mgmt-end-user',
+		    'itop-config-mgmt-storage',
+		    'itop-config-mgmt-virtualization',
+		    'itop-service-mgmt-enterprise',
+		    'itop-ticket-mgmt-simple-ticket',
+			'itop-ticket-mgmt-simple-ticket-enhanced-portal',
+		];
+		if ($bInstallationOptionalChoicesChecked){
+			$aExpectedExtensions []= "itop-problem-mgmt";
+			$aExpectedExtensions []= 'itop-kown-error-mgmt';
+		}
+		sort($aExpectedExtensions);
+		$this->assertEquals($aExpectedExtensions, $aGetAfterComputationSelectedExtensions);
+
+		$this->ValidateNonItilExtensionComputation($oInstallationFileService, $bInstallationOptionalChoicesChecked);
 	}
 
 	/**
 	 * @dataProvider ItilExtensionProvider
 	 */
-	public function testProcessInstallationChoicesWithItilChoices(array $aSelectedExtensions, bool $bKnownMgtSelected) {
+	public function testProcessInstallationChoicesWithItilChoices(array $aSelectedExtensions, bool $bKnownMgtSelected, bool $bCoreMgtSelected) {
 		$sPath = $this->GetInstallationPath();
 		$oInstallationFileService = new \InstallationFileService($sPath, 'production', $aSelectedExtensions, false);
 		$oProductionEnv = $this->createMock(\RunTimeEnvironment::class);
@@ -255,6 +277,8 @@ class InstallationFileServiceTest extends ItopTestCase {
 		sort($aExpectedUnselectedModules);
 		sort($aUnselectedModules);
 		$this->assertEquals($aExpectedUnselectedModules, $aUnselectedModules);
+
+		$this->ValidateItilExtensionComputation($oInstallationFileService, $bKnownMgtSelected, $bCoreMgtSelected);
 	}
 
 	public function GetDefaultModulesProvider() {
@@ -334,6 +358,55 @@ class InstallationFileServiceTest extends ItopTestCase {
 		$this->checkModuleList("unvisible", $aUnvisibleModules, $aSelectedModules);
 		$this->checkModuleList("auto-select", $aAutoSelectedModules, $aSelectedModules);
 		$this->assertEquals([], $aSelectedModules, "there should be no more modules remaining apart from below lists");
+
+		$this->ValidateNonItilExtensionComputation($oInstallationFileService, $bInstallationOptionalChoicesChecked);
+	}
+
+	private function ValidateNonItilExtensionComputation($oInstallationFileService, bool $bInstallationOptionalChoicesChecked) {
+		$aGetAfterComputationSelectedExtensions = $oInstallationFileService->GetAfterComputationSelectedExtensions();
+		sort($aGetAfterComputationSelectedExtensions);
+		$aExpectedExtensions = [
+			'itop-change-mgmt-simple',
+			'itop-config-mgmt-core',
+			'itop-config-mgmt-datacenter',
+			'itop-config-mgmt-end-user',
+			'itop-config-mgmt-storage',
+			'itop-config-mgmt-virtualization',
+			'itop-service-mgmt-enterprise',
+			'itop-ticket-mgmt-simple-ticket',
+			'itop-ticket-mgmt-simple-ticket-enhanced-portal',
+		];
+		if ($bInstallationOptionalChoicesChecked){
+			$aExpectedExtensions []= "itop-problem-mgmt";
+			$aExpectedExtensions []= 'itop-kown-error-mgmt';
+		}
+		sort($aExpectedExtensions);
+		$this->assertEquals($aExpectedExtensions, $aGetAfterComputationSelectedExtensions);
+	}
+
+	private function ValidateItilExtensionComputation($oInstallationFileService, bool $bKnownMgtSelected, bool $bCoreMgtSelected) {
+		$aGetAfterComputationSelectedExtensions = $oInstallationFileService->GetAfterComputationSelectedExtensions();
+		sort($aGetAfterComputationSelectedExtensions);
+		$aExpectedExtensions = [
+			'itop-change-mgmt-itil',
+			'itop-config-mgmt-datacenter',
+			'itop-config-mgmt-end-user',
+			'itop-config-mgmt-storage',
+			'itop-config-mgmt-virtualization',
+			'itop-service-mgmt-enterprise',
+			'itop-ticket-mgmt-itil',
+			'itop-ticket-mgmt-itil-enhanced-portal',
+			'itop-ticket-mgmt-itil-incident',
+			'itop-ticket-mgmt-itil-user-request',
+		];
+		if ($bCoreMgtSelected){
+			$aExpectedExtensions []= 'itop-config-mgmt-core';
+		}
+		if ($bKnownMgtSelected){
+			$aExpectedExtensions []= 'itop-kown-error-mgmt';
+		}
+		sort($aExpectedExtensions);
+		$this->assertEquals($aExpectedExtensions, $aGetAfterComputationSelectedExtensions);
 	}
 
 	private function GetSelectedItilExtensions(bool $coreExtensionIncluded, bool $bKnownMgtIncluded) : array {
@@ -367,18 +440,22 @@ class InstallationFileServiceTest extends ItopTestCase {
 			'all itil extensions + INCLUDING known-error-mgt' => [
 				'aSelectedExtensions' => $this->GetSelectedItilExtensions(true, true),
 				'bKnownMgtSelected' => true,
+				'bCoreMgtSelected' => true,
 			],
 			'all itil extensions WITHOUT known-error-mgt' => [
 				'aSelectedExtensions' => $this->GetSelectedItilExtensions(true, false),
 				'bKnownMgtSelected' => false,
+				'bCoreMgtSelected' => true,
 			],
 			'all itil extensions WITHOUT core mandatory ones + INCLUDING known-error-mgt' => [
 				'aSelectedExtensions' => $this->GetSelectedItilExtensions(false, true),
 				'bKnownMgtSelected' => true,
+				'bCoreMgtSelected' => false,
 			],
 			'all itil extensions WITHOUT core mandatory ones and WITHOUT known-error-mgt' => [
 				'aSelectedExtensions' => $this->GetSelectedItilExtensions(false, false),
 				'bKnownMgtSelected' => false,
+				'bCoreMgtSelected' => false,
 			],
 		];
 	}
@@ -386,7 +463,7 @@ class InstallationFileServiceTest extends ItopTestCase {
 	/**
 	 * @dataProvider ItilExtensionProvider
 	 */
-	public function testGetAllSelectedModules_withItilExtensions(array $aSelectedExtensions, bool $bKnownMgtSelected) {
+	public function testGetAllSelectedModules_withItilExtensions(array $aSelectedExtensions, bool $bKnownMgtSelected, bool $bCoreMgtSelected) {
 		$sPath = $this->GetInstallationPath();
 		$oInstallationFileService = new \InstallationFileService($sPath, 'production', $aSelectedExtensions);
 
@@ -448,6 +525,8 @@ class InstallationFileServiceTest extends ItopTestCase {
 		$this->checkModuleList("unvisible", $aUnvisibleModules, $aSelectedModules);
 		$this->checkModuleList("auto-select", $aAutoSelectedModules, $aSelectedModules);
 		$this->assertEquals([], $aSelectedModules, "there should be no more modules remaining apart from below lists");
+
+		$this->ValidateItilExtensionComputation($oInstallationFileService, $bKnownMgtSelected, $bCoreMgtSelected);
 	}
 
 	private function checkModuleList(string $sModuleCategory, array $aExpectedModuleList, array &$aSelectedModules) {