diff --git a/src/Stringifiers/ObjectStringifier.php b/src/Stringifiers/ObjectStringifier.php
index d13a3a1..9c278a9 100644
--- a/src/Stringifiers/ObjectStringifier.php
+++ b/src/Stringifiers/ObjectStringifier.php
@@ -56,7 +56,15 @@ public function stringify(mixed $raw, int $depth): ?string
      */
     private function getProperties(ReflectionObject $reflectionObject, object $object, int $depth): array
     {
-        $reflectionProperties = $reflectionObject->getProperties();
+        $reflectionProperties = [];
+        while ($reflectionObject) {
+            $reflectionProperties = [
+                ...$reflectionProperties,
+                ...$reflectionObject->getProperties(),
+            ];
+            $reflectionObject = $reflectionObject->getParentClass();
+        }
+
         if (count($reflectionProperties) === 0) {
             return [];
         }
diff --git a/tests/fixtures/ParentWithProperties.php b/tests/fixtures/ParentWithProperties.php
new file mode 100644
index 0000000..9d69022
--- /dev/null
+++ b/tests/fixtures/ParentWithProperties.php
@@ -0,0 +1,16 @@
+<?php
+
+/*
+ * This file is part of Respect/Stringifier.
+ * Copyright (c) Henrique Moody <henriquemoody@gmail.com>
+ * SPDX-License-Identifier: MIT
+ */
+
+declare(strict_types=1);
+
+// phpcs:disable PSR1.Classes.ClassDeclaration.MissingNamespace
+
+abstract class ParentWithProperties
+{
+    private string $privateProperty = 'something'; // @phpstan-ignore-line
+}
diff --git a/tests/fixtures/WithProperties.php b/tests/fixtures/WithProperties.php
index 773d4a9..8d69804 100644
--- a/tests/fixtures/WithProperties.php
+++ b/tests/fixtures/WithProperties.php
@@ -10,11 +10,9 @@
 
 // phpcs:disable PSR1.Classes.ClassDeclaration.MissingNamespace
 
-class WithProperties
+class WithProperties extends ParentWithProperties
 {
     public bool $publicProperty = true;
 
     protected int $protectedProperty = 42;
-
-    private string $privateProperty = 'something'; // @phpstan-ignore-line
 }
diff --git a/tests/unit/Stringifiers/ObjectStringifierTest.php b/tests/unit/Stringifiers/ObjectStringifierTest.php
index f157173..b3df836 100644
--- a/tests/unit/Stringifiers/ObjectStringifierTest.php
+++ b/tests/unit/Stringifiers/ObjectStringifierTest.php
@@ -13,6 +13,7 @@
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\Attributes\Test;
 use PHPUnit\Framework\TestCase;
+use ReflectionClass;
 use ReflectionObject;
 use Respect\Stringifier\Stringifiers\ObjectStringifier;
 use Respect\Stringifier\Test\Double\FakeQuoter;
@@ -22,6 +23,7 @@
 use WithProperties;
 use WithUninitializedProperties;
 
+use function assert;
 use function sprintf;
 
 #[CoversClass(ObjectStringifier::class)]
@@ -71,6 +73,8 @@ public function itShouldStringifyRawValueWhenItIsAnObjectWithProperties(): void
         $sut = new ObjectStringifier($stringifier, $quoter, self::MAXIMUM_DEPTH, self::MAXIMUM_NUMBER_OF_PROPERTIES);
 
         $relection = new ReflectionObject($raw);
+        $parentReflection = $relection->getParentClass();
+        assert($parentReflection instanceof ReflectionClass);
 
         $actual = $sut->stringify($raw, self::DEPTH);
         $expected = $quoter->quote(
@@ -79,7 +83,10 @@ public function itShouldStringifyRawValueWhenItIsAnObjectWithProperties(): void
                 $relection->getName(),
                 $stringifier->stringify($relection->getProperty('publicProperty')->getValue($raw), self::DEPTH + 1),
                 $stringifier->stringify($relection->getProperty('protectedProperty')->getValue($raw), self::DEPTH + 1),
-                $stringifier->stringify($relection->getProperty('privateProperty')->getValue($raw), self::DEPTH + 1),
+                $stringifier->stringify(
+                    $parentReflection->getProperty('privateProperty')->getValue($raw),
+                    self::DEPTH + 1,
+                ),
             ),
             self::DEPTH
         );