diff --git a/tests/Models/NullProjectAttributeTest.php b/tests/Models/NullProjectAttributeTest.php
index c406961..8306bfe 100644
--- a/tests/Models/NullProjectAttributeTest.php
+++ b/tests/Models/NullProjectAttributeTest.php
@@ -37,7 +37,7 @@ final class NullProjectAttributeTest extends \PHPUnit\Framework\TestCase
     public function testId() : void
     {
         $null = new NullProjectAttribute(2);
-        self::assertEquals(2, $null->getId());
+        self::assertEquals(2, $null->id);
     }
 
     /**
diff --git a/tests/Models/NullProjectAttributeTypeTest.php b/tests/Models/NullProjectAttributeTypeTest.php
index 76ce0a1..56e7850 100644
--- a/tests/Models/NullProjectAttributeTypeTest.php
+++ b/tests/Models/NullProjectAttributeTypeTest.php
@@ -37,7 +37,7 @@ final class NullProjectAttributeTypeTest extends \PHPUnit\Framework\TestCase
     public function testId() : void
     {
         $null = new NullProjectAttributeType(2);
-        self::assertEquals(2, $null->getId());
+        self::assertEquals(2, $null->id);
     }
 
     /**
diff --git a/tests/Models/NullProjectAttributeValueTest.php b/tests/Models/NullProjectAttributeValueTest.php
index ff85aa2..2a2b3e5 100644
--- a/tests/Models/NullProjectAttributeValueTest.php
+++ b/tests/Models/NullProjectAttributeValueTest.php
@@ -37,7 +37,7 @@ final class NullProjectAttributeValueTest extends \PHPUnit\Framework\TestCase
     public function testId() : void
     {
         $null = new NullProjectAttributeValue(2);
-        self::assertEquals(2, $null->getId());
+        self::assertEquals(2, $null->id);
     }
 
     /**