diff --git a/library/Icinga/Application/ApplicationBootstrap.php b/library/Icinga/Application/ApplicationBootstrap.php
index e265b91ee..53c2c70c7 100644
--- a/library/Icinga/Application/ApplicationBootstrap.php
+++ b/library/Icinga/Application/ApplicationBootstrap.php
@@ -134,18 +134,20 @@ abstract class ApplicationBootstrap
         $this->vendorDir = $baseDir . '/library/vendor';
         $this->libDir = realpath(__DIR__ . '/../..');
 
+        $this->setupAutoloader();
+
         if ($configDir === null) {
             if (array_key_exists('ICINGAWEB_CONFIGDIR', $_SERVER)) {
                 $configDir = $_SERVER['ICINGAWEB_CONFIGDIR'];
             } else {
-                $configDir = '/etc/icingaweb2';
+                $configDir = Platform::isWindows()
+                    ? $baseDir . DIRECTORY_SEPARATOR . 'config'
+                    : '/etc/icingaweb2';
             }
         }
         $canonical = realpath($configDir);
         $this->configDir = $canonical ? $canonical : $configDir;
 
-        $this->setupAutoloader();
-
         set_include_path(
             implode(
                 PATH_SEPARATOR,