diff --git a/src/Box.php b/src/Box.php
index 96e5e9143..232c8f105 100644
--- a/src/Box.php
+++ b/src/Box.php
@@ -113,7 +113,7 @@ public function startBuffering(): void
     }
 
     /**
-     * @param callable(SymbolsRegistry, string): void $dumpAutoload
+     * @param callable(SymbolsRegistry, string, string[]): void $dumpAutoload
      */
     public function endBuffering(?callable $dumpAutoload): void
     {
diff --git a/src/Composer/AutoloadDumper.php b/src/Composer/AutoloadDumper.php
index 6a4133c88..651a16f00 100644
--- a/src/Composer/AutoloadDumper.php
+++ b/src/Composer/AutoloadDumper.php
@@ -14,15 +14,18 @@
 
 namespace KevinGH\Box\Composer;
 
+use Humbug\PhpScoper\Autoload\ComposerFileHasher;
 use Humbug\PhpScoper\Autoload\ScoperAutoloadGenerator;
 use Humbug\PhpScoper\Symbol\SymbolsRegistry;
 use KevinGH\Box\NotInstantiable;
 use UnexpectedValueException;
+use function array_column;
 use function array_map;
 use function explode;
 use function implode;
 use function preg_match;
 use function preg_replace;
+use function sprintf;
 use function str_replace;
 use const PHP_EOL;
 
@@ -30,15 +33,26 @@ final class AutoloadDumper
 {
     use NotInstantiable;
 
+    private const PACKAGE_PATH_REGEX = '~^%s/(?<vendor>[^/]+?/[^/]+?)/(?<path>.+?)$~';
+
+    /**
+     * @param string[] $excludedComposerAutoloadFiles
+     */
     public static function generateAutoloadStatements(
         SymbolsRegistry $symbolsRegistry,
-        array $excludedComposerAutoloadFileHashes,
+        string $vendorDir,
+        array $excludedComposerAutoloadFiles,
         string $autoloadContents,
     ): string {
         if (0 === $symbolsRegistry->count()) {
             return $autoloadContents;
         }
 
+        $excludedComposerAutoloadFileHashes = self::getExcludedComposerAutoloadFileHashes(
+            $vendorDir,
+            $excludedComposerAutoloadFiles,
+        );
+
         $autoloadContents = self::extractInlinedAutoloadContents($autoloadContents);
         $scoperStatements = self::getOriginalScoperAutoloaderContents(
             $symbolsRegistry,
@@ -59,6 +73,26 @@ public static function generateAutoloadStatements(
         return self::cleanupDuplicateLineReturns($mergedAutoloadContents);
     }
 
+    /**
+     * @param string[] $excludedComposerAutoloadFiles
+     */
+    private static function getExcludedComposerAutoloadFileHashes(
+        string $vendorDir,
+        array $excludedComposerAutoloadFiles,
+    ): array
+    {
+        $fileHashGenerator = new ComposerFileHasher(
+            '',
+            $excludedComposerAutoloadFiles,
+            sprintf(
+                self::PACKAGE_PATH_REGEX,
+                $vendorDir,
+            ),
+        );
+
+        return $fileHashGenerator->generateHashes();
+    }
+
     private static function extractInlinedAutoloadContents(string $autoloadContents): string
     {
         $autoloadContents = str_replace('<?php', '', $autoloadContents);
diff --git a/src/Composer/ComposerOrchestrator.php b/src/Composer/ComposerOrchestrator.php
index da8f7b338..f3ecf2eb9 100644
--- a/src/Composer/ComposerOrchestrator.php
+++ b/src/Composer/ComposerOrchestrator.php
@@ -110,11 +110,20 @@ public function checkVersion(): void
         }
     }
 
+    /**
+     * @param SymbolsRegistry $symbolsRegistry
+     * @param string $prefix
+     * @param bool $excludeDevFiles
+     * @param string[] $excludedComposerAutoloadFiles Relative paths of the files that were not scoped hence which need
+     *                                                to be configured as loaded to Composer as otherwise they would be
+     *                                                autoloaded twice.
+     * @return void
+     */
     public function dumpAutoload(
         SymbolsRegistry $symbolsRegistry,
         string $prefix,
         bool $excludeDevFiles,
-        array $excludedComposerAutoloadFileHashes,
+        array $excludedComposerAutoloadFiles,
     ): void {
         $this->dumpAutoloader(true === $excludeDevFiles);
 
@@ -122,17 +131,22 @@ public function dumpAutoload(
             return;
         }
 
-        $autoloadFile = $this->getVendorDir().'/autoload.php';
+        $vendorDir = $this->getVendorDir();
+        $autoloadFile = $vendorDir .'/autoload.php';
 
         $autoloadContents = AutoloadDumper::generateAutoloadStatements(
             $symbolsRegistry,
-            $excludedComposerAutoloadFileHashes,
+            $vendorDir,
+            $excludedComposerAutoloadFiles,
             $this->fileSystem->getFileContents($autoloadFile),
         );
 
         $this->fileSystem->dumpFile($autoloadFile, $autoloadContents);
     }
 
+    /**
+     * @return string The vendor-dir directory path relative to its composer.json.
+     */
     public function getVendorDir(): string
     {
         $vendorDirProcess = $this->processFactory->getVendorDirProcess();