diff --git a/tests/Models/NullItemRelationTest.php b/tests/Models/NullItemRelationTest.php
new file mode 100644
index 0000000..8657249
--- /dev/null
+++ b/tests/Models/NullItemRelationTest.php
@@ -0,0 +1,52 @@
+<?php
+/**
+ * Jingga
+ *
+ * PHP Version 8.1
+ *
+ * @package   tests
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 2.0
+ * @version   1.0.0
+ * @link      https://jingga.app
+ */
+declare(strict_types=1);
+
+namespace Modules\ItemManagement\tests\Models;
+
+use Modules\ItemManagement\Models\NullItemRelation;
+
+/**
+ * @internal
+ */
+final class NullItemRelationTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @covers Modules\ItemManagement\Models\NullItemRelation
+     * @group framework
+     */
+    public function testNull() : void
+    {
+        self::assertInstanceOf('\Modules\ItemManagement\Models\ItemRelation', new NullItemRelation());
+    }
+
+    /**
+     * @covers Modules\ItemManagement\Models\NullItemRelation
+     * @group framework
+     */
+    public function testId() : void
+    {
+        $null = new NullItemRelation(2);
+        self::assertEquals(2, $null->getId());
+    }
+
+    /**
+     * @covers Modules\ItemManagement\Models\NullItemRelation
+     * @group framework
+     */
+    public function testJsonSerialize() : void
+    {
+        $null = new NullItemRelation(2);
+        self::assertEquals(['id' => 2], $null);
+    }
+}
diff --git a/tests/Models/NullItemRelationTypeTest.php b/tests/Models/NullItemRelationTypeTest.php
new file mode 100644
index 0000000..735abb1
--- /dev/null
+++ b/tests/Models/NullItemRelationTypeTest.php
@@ -0,0 +1,52 @@
+<?php
+/**
+ * Jingga
+ *
+ * PHP Version 8.1
+ *
+ * @package   tests
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 2.0
+ * @version   1.0.0
+ * @link      https://jingga.app
+ */
+declare(strict_types=1);
+
+namespace Modules\ItemManagement\tests\Models;
+
+use Modules\ItemManagement\Models\NullItemRelationType;
+
+/**
+ * @internal
+ */
+final class NullItemRelationTypeTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @covers Modules\ItemManagement\Models\NullItemRelationType
+     * @group framework
+     */
+    public function testNull() : void
+    {
+        self::assertInstanceOf('\Modules\ItemManagement\Models\ItemRelationType', new NullItemRelationType());
+    }
+
+    /**
+     * @covers Modules\ItemManagement\Models\NullItemRelationType
+     * @group framework
+     */
+    public function testId() : void
+    {
+        $null = new NullItemRelationType(2);
+        self::assertEquals(2, $null->getId());
+    }
+
+    /**
+     * @covers Modules\ItemManagement\Models\NullItemRelationType
+     * @group framework
+     */
+    public function testJsonSerialize() : void
+    {
+        $null = new NullItemRelationType(2);
+        self::assertEquals(['id' => 2], $null);
+    }
+}