diff --git a/phpunit.xml b/phpunit.xml
index e78a54f3..92dc5a5b 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -7,6 +7,9 @@
         <testsuite name="Feature">
             <directory>./tests/Feature</directory>
         </testsuite>
+        <testsuite name="Unit">
+            <directory>./tests/Unit</directory>
+        </testsuite>
     </testsuites>
     <filter>
         <whitelist>
diff --git a/tests/Unit/Config/ConfigTest.php b/tests/Unit/Config/ConfigTest.php
new file mode 100644
index 00000000..ce11ebd6
--- /dev/null
+++ b/tests/Unit/Config/ConfigTest.php
@@ -0,0 +1,115 @@
+<?php
+
+namespace Engelsystem\Test\Config;
+
+use Engelsystem\Config\Config;
+use PHPUnit\Framework\TestCase;
+
+class ConfigTest extends TestCase
+{
+    /**
+     * @covers \Engelsystem\Config\Config::get
+     */
+    public function testGet()
+    {
+        $config = new Config();
+
+        $config->set('test', 'FooBar');
+        $this->assertEquals(['test' => 'FooBar'], $config->get(null));
+        $this->assertEquals('FooBar', $config->get('test'));
+
+        $this->assertEquals('defaultValue', $config->get('notExisting', 'defaultValue'));
+
+        $this->assertNull($config->get('notExisting'));
+    }
+
+    /**
+     * @covers \Engelsystem\Config\Config::set
+     */
+    public function testSet()
+    {
+        $config = new Config();
+
+        $config->set('test', 'FooBar');
+        $this->assertEquals('FooBar', $config->get('test'));
+
+        $config->set([
+            'name' => 'Engelsystem',
+            'mail' => ['user' => 'test'],
+        ]);
+        $this->assertEquals('Engelsystem', $config->get('name'));
+        $this->assertEquals(['user' => 'test'], $config->get('mail'));
+    }
+
+    /**
+     * @covers \Engelsystem\Config\Config::has
+     */
+    public function testHas()
+    {
+        $config = new Config();
+
+        $this->assertFalse($config->has('test'));
+
+        $config->set('test', 'FooBar');
+        $this->assertTrue($config->has('test'));
+    }
+
+    /**
+     * @covers \Engelsystem\Config\Config::remove
+     */
+    public function testRemove()
+    {
+        $config = new Config();
+        $config->set(['foo' => 'bar', 'test' => '123']);
+
+        $config->remove('foo');
+        $this->assertEquals(['test' => '123'], $config->get(null));
+    }
+
+    /**
+     * @covers \Engelsystem\Config\Config::__get
+     */
+    public function testMagicGet()
+    {
+        $config = new Config();
+
+        $config->set('test', 'FooBar');
+        $this->assertEquals('FooBar', $config->test);
+    }
+
+    /**
+     * @covers \Engelsystem\Config\Config::__set
+     */
+    public function testMagicSet()
+    {
+        $config = new Config();
+
+        $config->test = 'FooBar';
+        $this->assertEquals('FooBar', $config->get('test'));
+    }
+
+    /**
+     * @covers \Engelsystem\Config\Config::__isset
+     */
+    public function testMagicIsset()
+    {
+        $config = new Config();
+
+        $this->assertFalse(isset($config->test));
+
+        $config->set('test', 'FooBar');
+        $this->assertTrue(isset($config->test));
+    }
+
+    /**
+     * @covers \Engelsystem\Config\Config::__unset
+     */
+    public function testMagicUnset()
+    {
+        $config = new Config();
+        $config->set(['foo' => 'bar', 'test' => '123']);
+
+        unset($config->foo);
+        $this->assertEquals(['test' => '123'], $config->get(null));
+    }
+}