diff --git a/src/Services/ProjectSystem/ProjectBuildHelper.php b/src/Services/ProjectSystem/ProjectBuildHelper.php
index e011d980..090f9e66 100644
--- a/src/Services/ProjectSystem/ProjectBuildHelper.php
+++ b/src/Services/ProjectSystem/ProjectBuildHelper.php
@@ -242,7 +242,11 @@ final readonly class ProjectBuildHelper
      * taking bulk pricing into account for N builds.
      */
     private function getBomEntryUnitPrice(ProjectBOMEntry $entry, int $number_of_builds, ?Currency $currency): ?BigDecimal
-    {
+    {        
+        if ($entry->getPart() && $entry->getPart()->getBuiltProject() instanceof Project){
+            return $this->calculateTotalBuildPrice($entry->getPart()->getBuiltProject(), 1, $entry->getPriceCurrency());
+        }
+        
         if ($entry->getPart() instanceof Part) {
             $total_qty = $entry->getQuantity() * $number_of_builds;
             $min_order = $this->pricedetailHelper->getMinOrderAmount($entry->getPart());
diff --git a/tests/Services/ProjectSystem/ProjectBuildHelperTest.php b/tests/Services/ProjectSystem/ProjectBuildHelperTest.php
index a30380db..1e311730 100644
--- a/tests/Services/ProjectSystem/ProjectBuildHelperTest.php
+++ b/tests/Services/ProjectSystem/ProjectBuildHelperTest.php
@@ -208,6 +208,33 @@ final class ProjectBuildHelperTest extends WebTestCase
         $this->assertTrue(BigDecimal::of('6.00')->isEqualTo($result));
     }
 
+    public function testCalculateTotalBuildPriceWithBuildPartFromSubproject(): void
+    {
+        $project = new Project();
+        $entry = new ProjectBOMEntry();
+        $entry->setPart($this->makePartWithPrice(1.50));
+        $entry->setQuantity(4);
+        $project->addBomEntry($entry);
+
+        $subproject = new Project();
+        $subentry = new ProjectBOMEntry();
+        $subentry->setPart($this->makePartWithPrice(3.5));
+        $subentry->setQuantity(3);
+        $subproject->addBomEntry($subentry);
+
+        $part = new Part();
+        $entry2 = new ProjectBOMEntry();
+        $entry2->setPart($part);
+        $entry2->setQuantity(2);
+        $part->setBuiltProject($subproject);
+        $project->addBomEntry($entry2);
+
+        // 4 × 1.50 + 2 x (3 x 3.5) = 27.00 for 1 build
+        $result = $this->service->calculateTotalBuildPrice($project, 1);
+        $this->assertNotNull($result);
+        $this->assertTrue(BigDecimal::of('27.00')->isEqualTo($result));
+    }
+    
     public function testCalculateUnitBuildPriceEqualsTotal(): void
     {
         $project = new Project();