diff --git a/app/conf/services.yaml b/app/conf/services.yaml
index 06c362c..dc93424 100644
--- a/app/conf/services.yaml
+++ b/app/conf/services.yaml
@@ -6,6 +6,9 @@ services:
 
     config:
         class: '\Magdev\Dossier\Service\ConfigService'
+
+    system:
+        class: '\Magdev\Dossier\Service\SystemService'
         
     monolog:
         class: '\Magdev\Dossier\Service\MonologService'
@@ -21,7 +24,7 @@ services:
         
     git:
         class: '\Magdev\Dossier\Service\GitService'
-        arguments: ['@config', '@monolog']
+        arguments: ['@config', '@monolog', '@system']
         
     translator:
         class: '\Magdev\Dossier\Service\TranslatorService'
diff --git a/src/Service/GitService.php b/src/Service/GitService.php
index b1acd5f..bfdd495 100644
--- a/src/Service/GitService.php
+++ b/src/Service/GitService.php
@@ -30,14 +30,8 @@
  
 namespace Magdev\Dossier\Service;
 
-// git branch | grep \* | cut -d ' ' -f2
-
 class GitService
 {
-    const MODE_OUTPUT = 1;
-    const MODE_RETURN = 2;
-    const MODE_LASTLINE = 3;
-    
     /**
      * Configuration service
      * @var \Magdev\Dossier\Service\ConfigService
@@ -50,17 +44,25 @@ class GitService
      */
     protected $logger = null;
     
+    /**
+     * System service
+     * @var \Magdev\Dossier\Service\SystemService
+     */
+    protected $system = null;
+    
     
     /**
      * Constructor
      *
      * @param \Magdev\Dossier\Service\ConfigService $config
      * @param \Magdev\Dossier\Service\MonologService $logger
+     * @param \Magdev\Dossier\Service\SystemService $system
      */
-    public function __construct(ConfigService $config, MonologService $logger)
+    public function __construct(ConfigService $config, MonologService $logger, SystemService $system)
     {
         $this->config = $config;
         $this->logger = $logger;
+        $this->system = $system;
     }
     
     
@@ -72,7 +74,7 @@ class GitService
     public function init(): bool
     {
         if (!$this->isGitRepository()) {
-            $this->exec('git init');
+            $this->system->exec('git init');
         }
         return $this->isGitRepository();
     }
@@ -88,7 +90,7 @@ class GitService
         if (!$this->isGitRepository()) {
             return $this->config->get('output.docname');
         }
-        return $this->exec('git branch | grep \\\* | cut -d \' \' -f2', self::MODE_LASTLINE);
+        return $this->system->exec('git branch | grep \\\* | cut -d \' \' -f2', self::MODE_LASTLINE);
     }
     
     
@@ -101,25 +103,4 @@ class GitService
     {
         return is_dir(PROJECT_ROOT.'/.git') && file_exists(PROJECT_ROOT.'/.git/HEAD');
     }
-    
-    
-    /**
-     * Execute a system command
-     * 
-     * @param string $cmd
-     * @param int $mode
-     * @param array $output
-     * @param int $return
-     * @return string|int|array
-     */
-    protected function exec(string $cmd, int $mode = self::MODE_OUTPUT, &$output = array(), int &$return = 0)
-    {
-        $lastline = exec($cmd, $output, $return);
-        switch ($mode) {
-            case self::MODE_LASTLINE:   return $lastline;
-            case self::MODE_RETURN:     return $return;
-            default:
-            case self::MODE_OUTPUT:     return $output;
-        }
-    }
 }
diff --git a/src/Service/SystemService.php b/src/Service/SystemService.php
new file mode 100644
index 0000000..2d4c12e
--- /dev/null
+++ b/src/Service/SystemService.php
@@ -0,0 +1,59 @@
+<?php
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 magdev
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author    magdev
+ * @copyright 2019 Marco Grätsch
+ * @package   magdev/dossier
+ * @license   http://opensource.org/licenses/MIT MIT License
+ */
+ 
+namespace Magdev\Dossier\Service;
+
+class SystemService
+{
+    const MODE_OUTPUT = 1;
+    const MODE_RETURN = 2;
+    const MODE_LASTLINE = 3;
+    
+    
+    /**
+     * Execute a system command
+     *
+     * @param string $cmd
+     * @param int $mode
+     * @param array $output
+     * @param int $return
+     * @return string|int|array
+     */
+    protected function exec(string $cmd, int $mode = self::MODE_OUTPUT, &$output = array(), int &$return = 0)
+    {
+        $lastline = exec($cmd, $output, $return);
+        switch ($mode) {
+            case self::MODE_LASTLINE:   return $lastline;
+            case self::MODE_RETURN:     return $return;
+            default:
+            case self::MODE_OUTPUT:     return $output;
+        }
+    }
+}