diff --git a/tests/Services/ProjectSystem/ProjectBuildHelperTest.php b/tests/Services/ProjectSystem/ProjectBuildHelperTest.php
index 94d991e7..418ce641 100644
--- a/tests/Services/ProjectSystem/ProjectBuildHelperTest.php
+++ b/tests/Services/ProjectSystem/ProjectBuildHelperTest.php
@@ -217,15 +217,15 @@ final class ProjectBuildHelperTest extends WebTestCase
         $project->addBomEntry($entry);
         
         $subproject = new Project();
-        $subproject->setParent($project);
         $subentry = new ProjectBOMEntry();
         $subentry->setPart($this->makePartWithPrice(3.5));
         $subentry->setQuantity(2);
         
+        $part = new Part();
         $entry2 = new ProjectBOMEntry();
-        $entry2->setPart(new Part());
+        $part->setBuiltProject($subproject);
+        $entry2->setPart($part);
         $entry2->setQuantity(2);
-        $subproject->setBuildPart($entry2->getPart());
         $project->addBomEntry($entry2);
 
         // 4 × 1.50 + 2 x (2 x 3.5) = 20.00 for 1 build