diff --git a/src/Service/GitService.php b/src/Service/GitService.php
index bfdd495..592bb05 100644
--- a/src/Service/GitService.php
+++ b/src/Service/GitService.php
@@ -90,7 +90,7 @@ class GitService
         if (!$this->isGitRepository()) {
             return $this->config->get('output.docname');
         }
-        return $this->system->exec('git branch | grep \\\* | cut -d \' \' -f2', self::MODE_LASTLINE);
+        return $this->system->exec('git branch | grep \\\* | cut -d \' \' -f2', SystemService::MODE_LASTLINE);
     }
     
     
diff --git a/src/Service/SystemService.php b/src/Service/SystemService.php
index 2d4c12e..6cfdf05 100644
--- a/src/Service/SystemService.php
+++ b/src/Service/SystemService.php
@@ -46,7 +46,7 @@ class SystemService
      * @param int $return
      * @return string|int|array
      */
-    protected function exec(string $cmd, int $mode = self::MODE_OUTPUT, &$output = array(), int &$return = 0)
+    public function exec(string $cmd, int $mode = self::MODE_OUTPUT, &$output = array(), int &$return = 0)
     {
         $lastline = exec($cmd, $output, $return);
         switch ($mode) {