diff --git a/.gitignore b/.gitignore
index 0934d2ca..219148f5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,7 @@
 /box.json
 /dist/
 /build/
+/fixtures/set004/scoper.inc.php
 /fixtures/*/vendor
 /vendor/
 /vendor-bin/box/vendor/
diff --git a/Makefile b/Makefile
index 69540f5a..00ecb345 100644
--- a/Makefile
+++ b/Makefile
@@ -29,7 +29,7 @@ build: bin/php-scoper src vendor vendor-bin/box/vendor scoper.inc.php
 	composer install --no-dev --prefer-dist
 
 	# Prefixes the code to be bundled
-	php -d zend.enable_gc=0 bin/php-scoper add-prefix --prefix=Isolated --output-dir=build/php-scoper --force
+	php -d zend.enable_gc=0 bin/php-scoper add-prefix --output-dir=build/php-scoper --force
 
 	# Re-dump the loader to account for the prefixing
 	# and optimize the loader
diff --git a/bin/php-scoper b/bin/php-scoper
index b7762a38..1ce60ee4 100755
--- a/bin/php-scoper
+++ b/bin/php-scoper
@@ -13,7 +13,9 @@
 
 namespace Humbug\PhpScoper;
 
+use Isolated\Symfony\Component\Finder\Finder as IsolatedFinder;
 use RuntimeException;
+use Symfony\Component\Finder\Finder;
 
 $findAutoload = function () {
     if (file_exists($autoload = __DIR__.'/../../../autoload.php')) {
@@ -39,8 +41,8 @@ $autoload = $findAutoload();
 require $autoload;
 
 // Exposes the finder used by PHP-Scoper PHAR to allow its usage in the configuration file.
-if (false === class_exists('Isolated\Symfony\Component\Finder\Finder')) {
-    class_alias('Symfony\Component\Finder\Finder', 'Isolated\Symfony\Component\Finder\Finder');
+if (false === class_exists(IsolatedFinder::class)) {
+    class_alias(Finder::class, IsolatedFinder::class);
 }
 
 $isVeryVerbose = array_reduce(
diff --git a/scoper.inc.php b/scoper.inc.php
index 55741aae..96b2fe3a 100644
--- a/scoper.inc.php
+++ b/scoper.inc.php
@@ -36,6 +36,9 @@
             'box.json.dist',
         ]),
     ],
+    'whitelist' => [
+        Finder::class,
+    ],
     'patchers' => [
         function (string $filePath, string $prefix, string $content): string {
             //