diff --git a/src/Config/ConfigServiceProvider.php b/src/Config/ConfigServiceProvider.php
index 01b648df..9fbccd68 100644
--- a/src/Config/ConfigServiceProvider.php
+++ b/src/Config/ConfigServiceProvider.php
@@ -3,24 +3,33 @@
 namespace Engelsystem\Config;
 
 use Engelsystem\Container\ServiceProvider;
+use Exception;
 
 class ConfigServiceProvider extends ServiceProvider
 {
+    /** @var array */
+    protected $configFiles = ['config.default.php', 'config.php'];
+
     public function register()
     {
-        $defaultConfigFile = config_path('config.default.php');
-        $configFile = config_path('config.php');
-
         $config = $this->app->make(Config::class);
         $this->app->instance('config', $config);
 
-        $config->set(require $defaultConfigFile);
+        foreach ($this->configFiles as $file) {
+            $file = config_path($file);
+
+            if (!file_exists($file)) {
+                continue;
+            }
 
-        if (file_exists($configFile)) {
             $config->set(array_replace_recursive(
                 $config->get(null),
-                require $configFile
+                require $file
             ));
         }
+
+        if (empty($config->get(null))) {
+            throw new Exception('Configuration not found');
+        }
     }
 }
diff --git a/tests/Unit/Config/ConfigServiceProviderTest.php b/tests/Unit/Config/ConfigServiceProviderTest.php
index c8be4b7d..998c0ba1 100644
--- a/tests/Unit/Config/ConfigServiceProviderTest.php
+++ b/tests/Unit/Config/ConfigServiceProviderTest.php
@@ -6,6 +6,7 @@ use Engelsystem\Application;
 use Engelsystem\Config\Config;
 use Engelsystem\Config\ConfigServiceProvider;
 use Engelsystem\Test\Unit\ServiceProviderTest;
+use Exception;
 use PHPUnit_Framework_MockObject_MockObject;
 
 class ConfigServiceProviderTest extends ServiceProviderTest
@@ -27,12 +28,15 @@ class ConfigServiceProviderTest extends ServiceProviderTest
         $this->setExpects($app, 'get', ['path.config'], __DIR__ . '/../../../config', $this->atLeastOnce());
 
         $this->setExpects($config, 'set', null, null, $this->exactly(2));
-        $this->setExpects($config, 'get', [null], []);
+        $config->expects($this->exactly(3))
+            ->method('get')
+            ->with(null)
+            ->willReturnOnConsecutiveCalls([], [], ['lor' => 'em']);
 
         $configFile = __DIR__ . '/../../../config/config.php';
         $configExists = file_exists($configFile);
         if (!$configExists) {
-            file_put_contents($configFile, '<?php return [];');
+            file_put_contents($configFile, '<?php return ["lor"=>"em"];');
         }
 
         $serviceProvider = new ConfigServiceProvider($app);
@@ -42,4 +46,29 @@ class ConfigServiceProviderTest extends ServiceProviderTest
             unlink($configFile);
         }
     }
+
+    /**
+     * @covers \Engelsystem\Config\ConfigServiceProvider::register()
+     */
+    public function testRegisterException()
+    {
+        /** @var PHPUnit_Framework_MockObject_MockObject|Config $config */
+        $config = $this->getMockBuilder(Config::class)
+            ->getMock();
+
+        $app = $this->getApp(['make', 'instance', 'get']);
+        Application::setInstance($app);
+
+        $this->setExpects($app, 'make', [Config::class], $config);
+        $this->setExpects($app, 'instance', ['config', $config]);
+        $this->setExpects($app, 'get', ['path.config'], __DIR__ . '/not_existing', $this->atLeastOnce());
+
+        $this->setExpects($config, 'set', null, null, $this->never());
+        $this->setExpects($config, 'get', [null], []);
+
+        $this->expectException(Exception::class);
+
+        $serviceProvider = new ConfigServiceProvider($app);
+        $serviceProvider->register();
+    }
 }