diff --git a/src/Illuminate/Filesystem/FilesystemAdapter.php b/src/Illuminate/Filesystem/FilesystemAdapter.php
index cc227173c5ac..1afce89fd430 100644
--- a/src/Illuminate/Filesystem/FilesystemAdapter.php
+++ b/src/Illuminate/Filesystem/FilesystemAdapter.php
@@ -75,7 +75,9 @@ public function __construct(FilesystemOperator $driver, FlysystemAdapter $adapte
         $this->driver = $driver;
         $this->adapter = $adapter;
         $this->config = $config;
-        $this->prefixer = new PathPrefixer($config['root'] ?? '');
+        $this->prefixer = new PathPrefixer(
+            $config['root'] ?? '', $config['directory_separator'] ?? DIRECTORY_SEPARATOR
+        );
     }
 
     /**