diff --git a/l10n_update.admin.inc b/l10n_update.admin.inc
index 688a0c9..8399943 100644
--- a/l10n_update.admin.inc
+++ b/l10n_update.admin.inc
@@ -451,7 +451,85 @@ function theme_l10n_update_edit_form_strings(array $variables) {
 }
 
 /**
- * Prepares variables for translation status information templates.
+ * Returns HTML for the language overview form.
+ *
+ * @param array $variables
+ *   An associative array containing:
+ *   - form: A render element representing the form.
+ * @return mixed
+ *
+ * @ingroup themeable
+ */
+function theme_l10n_update_languages_overview_form($variables) {
+  $form = $variables['form'];
+  $default = language_default();
+  $l10n_update_langcodes = variable_get('l10n_update_langcodes', array());
+  $rows = array();
+
+  foreach ($form['name'] as $key => $element) {
+    // Do not take form control structures.
+    if (is_array($element) && element_child($key)) {
+      // Disable checkbox for the default language, because it cannot be disabled.
+      if ($key == $default->language) {
+        $form['enabled'][$key]['#attributes']['disabled'] = 'disabled';
+      }
+
+      // Add invisible labels for the checkboxes and radio buttons in the table
+      // for accessibility. These changes are only required and valid when the
+      // form is themed as a table, so it would be wrong to perform them in the
+      // form constructor.
+      $title = drupal_render($form['name'][$key]);
+      $form['enabled'][$key]['#title'] = t('Enable !title', array('!title' => $title));
+      $form['enabled'][$key]['#title_display'] = 'invisible';
+      $form['site_default'][$key]['#title'] = t('Set !title as default', array('!title' => $title));
+      $form['site_default'][$key]['#title_display'] = 'invisible';
+      $rows[] = array(
+        'data' => array(
+          '<strong>' . $title . '</strong>',
+          drupal_render($form['native'][$key]),
+          check_plain($key),
+          !empty($l10n_update_langcodes[$key]) ? check_plain($l10n_update_langcodes[$key]) : check_plain($key),
+          drupal_render($form['direction'][$key]),
+          array('data' => drupal_render($form['enabled'][$key]), 'align' => 'center'),
+          drupal_render($form['site_default'][$key]),
+          drupal_render($form['weight'][$key]),
+          l(
+            t('edit'),
+            'admin/config/regional/language/edit/' . $key
+          ) . (($key != 'en' && $key != $default->language) ? ' ' . l(
+              t('delete'),
+              'admin/config/regional/language/delete/' . $key
+            ) : ''),
+        ),
+        'class' => array('draggable'),
+      );
+    }
+  }
+
+  $header = array(
+    array('data' => t('English name')),
+    array('data' => t('Native name')),
+    array('data' => t('Code')),
+    array('data' => t('l10n code')),
+    array('data' => t('Direction')),
+    array('data' => t('Enabled')),
+    array('data' => t('Default')),
+    array('data' => t('Weight')),
+    array('data' => t('Operations')),
+  );
+  $output = theme(
+    'table',
+    array('header' => $header, 'rows' => $rows, 'attributes' => array('id' => 'language-order'))
+  );
+  $output .= '<em>' . t('* l10n code is used to build file path to update translations.') . '</em>';
+  $output .= drupal_render_children($form);
+
+  drupal_add_tabledrag('language-order', 'order', 'sibling', 'language-order-weight');
+
+  return $output;
+}
+
+/** * Prepares variables for translation status information templates.
  *
  * Translation status information is displayed per language.
  *
diff --git a/l10n_update.install b/l10n_update.install
index 1d779ec..39f29d9 100644
--- a/l10n_update.install
+++ b/l10n_update.install
@@ -183,6 +183,7 @@ function l10n_update_uninstall() {
   variable_del('l10n_update_last_check');
   variable_del('l10n_update_download_store');
   variable_del('l10n_update_check_mode');
+  variable_del('l10n_update_langcodes');
 }
 
 /**
diff --git a/l10n_update.module b/l10n_update.module
index e9a2899..0f06be8 100644
--- a/l10n_update.module
+++ b/l10n_update.module
@@ -171,6 +171,10 @@ function l10n_update_theme() {
       'file' => 'l10n_update.admin.inc',
       'template' => 'l10n_update-translation-update-info',
     ),
+    'l10n_update_languages_overview_form' => array(
+      'render element' => 'form',
+      'file' => 'l10n_update.admin.inc',
+    ),
   );
 }
 /**
@@ -297,15 +301,70 @@ function l10n_update_form_alter(&$form, $form_state, $form_id) {
       break;
 
     case 'locale_languages_predefined_form':
+      $form['#submit'][] = 'l10n_update_languages_changed_submit';
+      break;
+
     case 'locale_languages_custom_form':
+      l10n_update_language_destination_form($form, $form_state);
       $form['#submit'][] = 'l10n_update_languages_changed_submit';
       break;
 
+    case 'locale_languages_edit_form':
+      l10n_update_language_destination_form($form, $form_state);
+      break;
+
     case 'locale_languages_delete_form':
       // A language is being deleted.
       $form['#submit'][] = 'l10n_update_languages_delete_submit';
       break;
+
+    case 'locale_languages_overview_form':
+      $form['#theme'] = 'l10n_update_languages_overview_form';
+      break;
+  }
+}
+
+/**
+ * Add field to specify remote language code.
+ */
+function l10n_update_language_destination_form(&$form, $form_state) {
+  // Put action button in last position.
+  $form['custom language']['actions']['#weight'] = 10;
+
+  if (!empty($form_state['build_info']['args'][0])) {
+    $langcode = $form_state['build_info']['args'][0];
+    $l10n_update_langcodes = variable_get('l10n_update_langcodes', array());
+    $l10n_langcode = !empty($l10n_update_langcodes[$langcode]) ? $l10n_update_langcodes[$langcode] : '';
+  }
+
+  // l10n language code field.
+  $form['custom language']['l10n_langcode'] = array(
+    '#type' => 'textfield',
+    '#title' => t('l10n language code'),
+    '#maxlength' => 12,
+    '#default_value' => isset($l10n_langcode) ? $l10n_langcode : '',
+    '#description' => t(
+      'Used by "l10n_update" module to retrieve files from Drupal servers. '.
+      'If missing, the language code will be used.'
+    ),
+  );
+
+  $form['#submit'][] = 'l10n_update_language_destination_form_submit';
+}
+
+/**
+ * Save destination language code.
+ */
+function l10n_update_language_destination_form_submit(&$form, $form_state) {
+  $l10n_update_langcodes = variable_get('l10n_update_langcodes', array());
+  $langcode = $form_state['values']['langcode'];
+  if (!empty($form_state['values']['l10n_langcode'])) {
+    $l10n_update_langcodes[$langcode] = $form_state['values']['l10n_langcode'];
+  }
+  else {
+    unset($l10n_update_langcodes[$langcode]);
   }
+  variable_set('l10n_update_langcodes', $l10n_update_langcodes);
 }
 
 /**
diff --git a/l10n_update.translation.inc b/l10n_update.translation.inc
index 4612ec5..5b8e422 100644
--- a/l10n_update.translation.inc
+++ b/l10n_update.translation.inc
@@ -226,10 +226,15 @@ function l10n_update_source_check_file($source) {
  *   - "keep": TRUE to keep the downloaded file.
  */
 function l10n_update_source_build($project, $langcode, $filename = NULL) {
+  // Remote mapping codes.
+  $l10n_update_langcodes = variable_get('l10n_update_langcodes', array());
+  $l10n_langcode = !empty($l10n_update_langcodes[$langcode]) ? check_plain($l10n_update_langcodes[$langcode]) : $langcode;
+
   // Create a source object with data of the project object.
   $source = clone $project;
   $source->project = $project->name;
   $source->langcode = $langcode;
+  $source->l10n_langcode = $l10n_langcode;
   $source->type = '';
   $source->timestamp = 0;
   $source->last_checked = 0;
@@ -306,11 +311,18 @@ function l10n_update_source_build($project, $langcode, $filename = NULL) {
  *   String with replaced placeholders.
  */
 function l10n_update_build_server_pattern($project, $template) {
+  if (!empty($project->l10n_langcode)) {
+    $langcode = $project->l10n_langcode;
+  }
+  elseif (isset($project->langcode)) {
+    $langcode = $project->langcode;
+  }
+
   $variables = array(
     '%project' => $project->name,
     '%release' => $project->version,
     '%core' => $project->core,
-    '%language' => isset($project->langcode) ? $project->langcode : '%language',
+    '%language' => isset($langcode) ? $langcode : '%language',
   );
   return strtr($template, $variables);
 }