diff --git a/tests/Models/NullInvestmentTest.php b/tests/Models/NullInvestmentTest.php
index bb585be..9c85b5e 100644
--- a/tests/Models/NullInvestmentTest.php
+++ b/tests/Models/NullInvestmentTest.php
@@ -37,7 +37,7 @@ final class NullInvestmentTest extends \PHPUnit\Framework\TestCase
     public function testId() : void
     {
         $null = new NullInvestment(2);
-        self::assertEquals(2, $null->getId());
+        self::assertEquals(2, $null->id);
     }
 
     /**