diff --git a/phpunit/src/TraitsTest.php b/phpunit/src/TraitsTest.php
index 4bb014e5..af6a7f27 100644
--- a/phpunit/src/TraitsTest.php
+++ b/phpunit/src/TraitsTest.php
@@ -198,7 +198,10 @@ public function testGenPropertyPromotion(): void
         $argInfo->type = 'php::Str';
 
         $result = $this->invoke('genPropertyPromotion', $argInfo);
-        $this->assertStringContainsString('this_.setProperty', $result);
+        $this->assertStringContainsString(
+            'typephp_write_property_scoped(this_, "title", title, nullptr)',
+            $result,
+        );
         $this->assertStringContainsString('title', $result);
     }
 
diff --git a/src/Generator/PropertyPromotion.php b/src/Generator/PropertyPromotion.php
index f59c1b99..3338c5bb 100644
--- a/src/Generator/PropertyPromotion.php
+++ b/src/Generator/PropertyPromotion.php
@@ -24,7 +24,11 @@ protected function genPropertyPromotion(ArgInfo $argInfo): string
             return 'this_.' . $this->getNativeObjectPropertyCppName($property, $this->classDef)
                 . ' = ' . $value . ';' . PHP_EOL;
         }
-        $code .= 'this_.setProperty(' . $this->genCharPtr($propertyName) . ', ' . $argInfo->name . ')';
+        $scope = $this->class !== ''
+            ? $this->getClassEntryPtr($this->getFullClassName())
+            : 'nullptr';
+        $code .= 'typephp_write_property_scoped(this_, '
+            . $this->genCharPtr($propertyName) . ', ' . $argInfo->name . ', ' . $scope . ')';
         $code .= ";\n";
         return $code;
     }
diff --git a/tests/compiler/object_ctor/promotion-inherited-private-scope.phpt b/tests/compiler/object_ctor/promotion-inherited-private-scope.phpt
new file mode 100644
index 00000000..3dec531d
--- /dev/null
+++ b/tests/compiler/object_ctor/promotion-inherited-private-scope.phpt
@@ -0,0 +1,29 @@
+--TEST--
+Constructor promotion writes inherited private promoted properties into the declared slot
+--FILE--
+<?php
+class ParentCls
+{
+    public function __construct(private string $name = "default") {}
+}
+
+class ChildCls extends ParentCls {}
+
+function main(): void
+{
+    $child = new ChildCls("hello");
+    var_dump($child);
+
+    $direct = new ParentCls("direct");
+    var_dump($direct);
+}
+?>
+--EXPECT--
+object(ChildCls)#1 (1) {
+  ["name":"ParentCls":private]=>
+  string(5) "hello"
+}
+object(ParentCls)#2 (1) {
+  ["name":"ParentCls":private]=>
+  string(6) "direct"
+}