diff --git a/src/Manager.php b/src/Manager.php
index 3cc4825..fe97053 100644
--- a/src/Manager.php
+++ b/src/Manager.php
@@ -61,7 +61,7 @@ class Manager
      */
     private ScopeFactoryInterface $scopeFactory;
 
-    public function __construct(ScopeFactoryInterface $scopeFactory = null)
+    public function __construct(?ScopeFactoryInterface $scopeFactory = null)
     {
         $this->scopeFactory = $scopeFactory ?: new ScopeFactory();
     }
@@ -72,7 +72,7 @@ public function __construct(ScopeFactoryInterface $scopeFactory = null)
     public function createData(
         ResourceInterface $resource,
         ?string $scopeIdentifier = null,
-        Scope $parentScopeInstance = null
+        ?Scope $parentScopeInstance = null
     ): Scope {
         if ($parentScopeInstance !== null) {
             return $this->scopeFactory->createChildScopeFor($this, $parentScopeInstance, $resource, $scopeIdentifier);
diff --git a/test/Serializer/DataArraySerializerTest.php b/test/Serializer/DataArraySerializerTest.php
index a95720b..d93b8d5 100644
--- a/test/Serializer/DataArraySerializerTest.php
+++ b/test/Serializer/DataArraySerializerTest.php
@@ -1,4 +1,4 @@
-<?php namespace PHPOpenSourceSaver\Fractal\Test\Resource;
+<?php namespace PHPOpenSourceSaver\Fractal\Test\Serializer;
 
 use PHPOpenSourceSaver\Fractal\Manager;
 use PHPOpenSourceSaver\Fractal\Resource\Collection;