diff --git a/tests/Models/NullMediaContentTest.php b/tests/Models/NullMediaContentTest.php
index e1103ea..1b84c0b 100644
--- a/tests/Models/NullMediaContentTest.php
+++ b/tests/Models/NullMediaContentTest.php
@@ -37,7 +37,7 @@ final class NullMediaContentTest extends \PHPUnit\Framework\TestCase
     public function testId() : void
     {
         $null = new NullMediaContent(2);
-        self::assertEquals(2, $null->getId());
+        self::assertEquals(2, $null->id);
     }
 
     /**
diff --git a/tests/Models/NullReferenceTest.php b/tests/Models/NullReferenceTest.php
index 232f7cc..5be554d 100644
--- a/tests/Models/NullReferenceTest.php
+++ b/tests/Models/NullReferenceTest.php
@@ -37,7 +37,7 @@ final class NullReferenceTest extends \PHPUnit\Framework\TestCase
     public function testId() : void
     {
         $null = new NullReference(2);
-        self::assertEquals(2, $null->getId());
+        self::assertEquals(2, $null->id);
     }
 
     /**