diff --git a/tests/Models/NullItemRelationTest.php b/tests/Models/NullItemRelationTest.php
index e3d5b59..8b9d183 100644
--- a/tests/Models/NullItemRelationTest.php
+++ b/tests/Models/NullItemRelationTest.php
@@ -37,7 +37,7 @@ final class NullItemRelationTest extends \PHPUnit\Framework\TestCase
     public function testId() : void
     {
         $null = new NullItemRelation(2);
-        self::assertEquals(2, $null->getId());
+        self::assertEquals(2, $null->id);
     }
 
     /**
diff --git a/tests/Models/NullItemRelationTypeTest.php b/tests/Models/NullItemRelationTypeTest.php
index 390c85a..662c764 100644
--- a/tests/Models/NullItemRelationTypeTest.php
+++ b/tests/Models/NullItemRelationTypeTest.php
@@ -37,7 +37,7 @@ final class NullItemRelationTypeTest extends \PHPUnit\Framework\TestCase
     public function testId() : void
     {
         $null = new NullItemRelationType(2);
-        self::assertEquals(2, $null->getId());
+        self::assertEquals(2, $null->id);
     }
 
     /**