diff --git a/lib/classes/User/Adapter.class.php b/lib/classes/User/Adapter.class.php
index 1680b2176e..4280d8ba0a 100644
--- a/lib/classes/User/Adapter.class.php
+++ b/lib/classes/User/Adapter.class.php
@@ -1398,95 +1398,6 @@ class User_Adapter implements User_Interface, cache_cacheableInterface
     return $lngs;
   }
 
-  public static function detectLanguage(registryInterface $registry, $setLng = null)
-  {
-    $avLanguages = self::avLanguages();
-    $sel = $askLng = $askLocale = '';
-
-    if ($setLng !== null)
-    {
-      $askLng = substr($setLng, 0, 2);
-      $askLocale = $setLng;
-    }
-    elseif (Session_Handler::isset_cookie('locale'))
-    {
-      $askLng = substr(Session_Handler::get_cookie('locale'), 0, 2);
-      $askLocale = Session_Handler::get_cookie('locale');
-    }
-    elseif (strlen($registry->get('GV_default_lng')) > 2)
-    {
-      $askLng = substr($registry->get('GV_default_lng'), 0, 2);
-      $askLocale = $registry->get('GV_default_lng');
-    }
-
-
-    if ($askLng != '' && isset($avLanguages[$askLng]) && isset($avLanguages[$askLng][$askLocale]))
-    {
-      $avLanguages[$askLng][$askLocale]['selected'] = true;
-      $sel = $askLocale;
-    }
-
-    if ($sel === '' && isset($_SERVER['HTTP_ACCEPT_LANGUAGE']))
-    {
-      $languages = explode(';', $_SERVER['HTTP_ACCEPT_LANGUAGE']);
-      $found = false;
-
-      foreach ($languages as $language)
-      {
-        $language = explode(',', strtolower($language));
-        if (count($language) != 2)
-          continue;
-
-        foreach ($language as $lang)
-        {
-          if (strpos($lang, '-') == 2 && strlen($lang) == 5)
-          {
-            $l = explode('-', $lang);
-            $l[0] = strtolower($l[0]);
-            $l[1] = strtoupper($l[1]);
-
-            if ($sel != '')
-            {
-              $found = true;
-              break;
-            }
-            $lang = implode('_', $l);
-            if (isset($avLanguages[$l[0]]))
-            {
-              if (!isset($avLanguages[$l[0]][$lang]))
-              {
-                $lang = end(array_keys($avLanguages[$l[0]]));
-              }
-              $avLanguages[$l[0]][$lang]['selected'] = true;
-              $sel = $lang;
-              $found = true;
-              break;
-            }
-          }
-        }
-        if ($found)
-          break;
-      }
-      if (!$found && array_key_exists(substr($registry->get('GV_default_lng'), 0, 2), $avLanguages))
-      {
-        $avLanguages[substr($registry->get('GV_default_lng'), 0, 2)][$registry->get('GV_default_lng')]['selected'] = true;
-        $sel = $registry->get('GV_default_lng');
-      }
-    }
-    if ($sel == '')
-    {
-      $key = end(array_keys($avLanguages));
-      $lang = end(array_keys($avLanguages[$key]));
-      $avLanguages[$key][$lang]['selected'] = true;
-      $sel = $lang;
-    }
-    Session_Handler::set_locale($sel);
-
-    $sel = explode('_', $sel);
-
-    return $avLanguages;
-  }
-
   public static function get_wrong_email_users(appbox $appbox)
   {