diff --git a/composer.json b/composer.json
index 08b1ed5..6e6bcc3 100644
--- a/composer.json
+++ b/composer.json
@@ -13,5 +13,9 @@
     },
     "require-dev": {
         "vimeo/psalm": "^5.4"
+    },
+    "config": {
+        "apcu-autoloader": true,
+        "classmap-authoritative": true
     }
 }
diff --git a/index.php b/index.php
index ee7fc4d..bc79c19 100644
--- a/index.php
+++ b/index.php
@@ -1,7 +1,7 @@
 <?php
 
 declare(strict_types=1);
-require_once 'vendor/autoload.php';
+require __DIR__ . '/vendor/autoload.php';
 
 use ICal\ICal;
 use Symfony\Component\HttpClient\CachingHttpClient;