diff --git a/Models/SessionElement.php b/Models/SessionElement.php
index 5fbd3f2..a06c354 100755
--- a/Models/SessionElement.php
+++ b/Models/SessionElement.php
@@ -32,7 +32,7 @@ class SessionElement implements \JsonSerializable, ArrayableInterface
      * @var int
      * @since 1.0.0
      */
-    private int $id = 0;
+    protected int $id = 0;
 
     /**
      * Session element status.
diff --git a/tests/Models/NullSession.php b/tests/Models/NullSession.php
new file mode 100644
index 0000000..ff1d492
--- /dev/null
+++ b/tests/Models/NullSession.php
@@ -0,0 +1,42 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   tests
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\HumanResourceTimeRecording\tests\Models;
+
+use Modules\HumanResourceTimeRecording\Models\NullSession;
+
+/**
+ * @internal
+ */
+final class Null extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @covers Modules\HumanResourceTimeRecording\Models\NullSession
+     * @group framework
+     */
+    public function testNull() : void
+    {
+        self::assertInstanceOf('\Modules\HumanResourceTimeRecording\Models\Session', new NullSession());
+    }
+
+    /**
+     * @covers Modules\HumanResourceTimeRecording\Models\NullSession
+     * @group framework
+     */
+    public function testId() : void
+    {
+        $null = new NullSession(2);
+        self::assertEquals(2, $null->getId());
+    }
+}
diff --git a/tests/Models/NullSessionElement.php b/tests/Models/NullSessionElement.php
new file mode 100644
index 0000000..1a58d38
--- /dev/null
+++ b/tests/Models/NullSessionElement.php
@@ -0,0 +1,42 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   tests
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\HumanResourceTimeRecording\tests\Models;
+
+use Modules\HumanResourceTimeRecording\Models\NullSessionElement;
+
+/**
+ * @internal
+ */
+final class Null extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @covers Modules\HumanResourceTimeRecording\Models\NullSessionElement
+     * @group framework
+     */
+    public function testNull() : void
+    {
+        self::assertInstanceOf('\Modules\HumanResourceTimeRecording\Models\SessionElement', new NullSessionElement());
+    }
+
+    /**
+     * @covers Modules\HumanResourceTimeRecording\Models\NullSessionElement
+     * @group framework
+     */
+    public function testId() : void
+    {
+        $null = new NullSessionElement(2);
+        self::assertEquals(2, $null->getId());
+    }
+}