diff --git a/tests/php-unit-tests/unitary-tests/core/DBObject/CRUDEventWithModifiedDataModelTest.php b/tests/php-unit-tests/unitary-tests/core/DBObject/CRUDEventWithModifiedDataModelTest.php
index f941be05d..2c0fae0a1 100644
--- a/tests/php-unit-tests/unitary-tests/core/DBObject/CRUDEventWithModifiedDataModelTest.php
+++ b/tests/php-unit-tests/unitary-tests/core/DBObject/CRUDEventWithModifiedDataModelTest.php
@@ -8,6 +8,7 @@ namespace Combodo\iTop\Test\UnitTest\Core\DBObject;
 
 use Combodo\iTop\Test\UnitTest\ItopCustomDatamodelTestCase;
 use DBObject\Utils\ClassesWithDebug;
+use DBObject\Utils\CRUDEventReceiver;
 use DBObject\Utils\EventTest;
 use IssueLog;
 use LogChannels;
@@ -34,14 +35,14 @@ class CRUDEventWithModifiedDataModelTest extends ItopCustomDatamodelTestCase
 	{
 		static::CleanCallCount();
 		parent::setUp();
-		static::$DEBUG_UNIT_TEST = false;
+		static::$DEBUG_UNIT_TEST = true;
 
 		if (static::$DEBUG_UNIT_TEST) {
 			echo '--- logging in '.APPROOT.static::$sLogFile."\n\n";
 			@unlink(APPROOT.static::$sLogFile);
 			IssueLog::Enable(APPROOT.static::$sLogFile);
 			$oConfig = utils::GetConfig();
-			$oConfig->Set('log_level_min', [LogChannels::DM_CRUD => 'Trace', LogChannels::EVENT_SERVICE => 'Trace']);
+			$oConfig->Set('log_level_min', [LogChannels::DM_CRUD => 'Debug', LogChannels::EVENT_SERVICE => 'Trace']);
 		}
 	}
 
@@ -56,16 +57,24 @@ class CRUDEventWithModifiedDataModelTest extends ItopCustomDatamodelTestCase
 		parent::tearDown();
 	}
 
+	/*
+	 * Test that when an object is deleted while having a link set with php computation
+	 * linked to a nullable external key, the db_links_changed event is not fired
+	 */
 	public function testDBLinksChangedNotCalledOnDeletedObjects()
 	{
+		$oEventReceiver = new CRUDEventReceiver($this);
+		$oEventReceiver->RegisterCRUDEventListeners(EVENT_DB_LINKS_CHANGED, 'TestDBObject');
+
 		$sObjectParentKey = $this->GivenObjectInDB('TestDBObject', ['name' => 'parent']);
-		$sObjectChildKey = $this->GivenObjectInDB('TestDBObject', ['name' => 'child', 'parent_id' => $sObjectParentKey]);
+		$oChild = $this->createObject('TestDBObject', ['name' => 'child', 'parent_id' => $sObjectParentKey]);
+		$this->AssertEventCountEquals(1, EVENT_DB_LINKS_CHANGED, 'Event EVENT_DB_LINKS_CHANGED should have been thrown on child creation');
 
 		$oParent = MetaModel::GetObject('TestDBObject', $sObjectParentKey);
 		static::CleanCallCount();
 		$oParent->DBDelete();
 
-		$oChild = MetaModel::GetObject('TestDBObject', $sObjectChildKey);
+		$oChild->Reload();
 		$this->assertEquals(0, $oChild->Get('parent_id'));
 		$this->AssertEventCountEquals(0, EVENT_DB_LINKS_CHANGED, 'Event EVENT_DB_LINKS_CHANGED should not have been thrown on deleted objects');
 	}
diff --git a/tests/php-unit-tests/unitary-tests/core/DBObject/Delta/dbobjecttest.xml b/tests/php-unit-tests/unitary-tests/core/DBObject/Delta/dbobjecttest.xml
index af58c4d92..20c31528e 100644
--- a/tests/php-unit-tests/unitary-tests/core/DBObject/Delta/dbobjecttest.xml
+++ b/tests/php-unit-tests/unitary-tests/core/DBObject/Delta/dbobjecttest.xml
@@ -19,15 +19,23 @@
           <default_value/>
           <is_null_allowed>false</is_null_allowed>
           <validation_pattern/>
-          <tracking_level>all</tracking_level>
+          <tracking_level>none</tracking_level>
         </field>
-        <field id="parent_id" xsi:type="AttributeHierarchicalKey">
+        <field id="parent_id" xsi:type="AttributeExternalKey">
           <sql>parent_id</sql>
           <filter/>
           <dependencies/>
           <is_null_allowed>true</is_null_allowed>
+          <target_class>TestDBObject</target_class>
           <on_target_delete>DEL_AUTO</on_target_delete>
-          <tracking_level>all</tracking_level>
+          <tracking_level>none</tracking_level>
+          <label>Test Object</label>
+        </field>
+        <field id="children_list" xsi:type="AttributeLinkedSet">
+          <linked_class>TestDBObject</linked_class>
+          <ext_key_to_me>parent_id</ext_key_to_me>
+          <count_min>0</count_min>
+          <count_max>0</count_max>
           <with_php_computation>true</with_php_computation>
         </field>
       </fields>