diff --git a/core/modules/language/language.admin.inc b/core/modules/language/language.admin.inc
index b388986..8056fd1 100644
--- a/core/modules/language/language.admin.inc
+++ b/core/modules/language/language.admin.inc
@@ -807,3 +807,183 @@ function language_negotiation_configure_session_form($form, &$form_state) {
 
   return system_settings_form($form);
 }
+
+/**
+ * Builds the browser language negotiation method configuration form.
+ */
+function language_negotiation_configure_browser_form($form, &$form_state) {
+  $form = array();
+
+  $form['info'] = array(
+    '#type' => 'markup',
+    '#markup' => t("You can add custom mappings to map browser languages to Drupal languages."),
+  );
+
+  $form['mappings'] = array(
+    '#type' => 'container',
+    '#tree' => TRUE,
+    '#theme' => 'language_negotiation_configure_browser_form_table',
+  );
+
+  $mappings = language_get_mappings();
+  foreach ($mappings as $browser_langcode => $drupal_langcode) {
+    $form['mappings'][$browser_langcode] = array(
+      'browser_langcode' => array(
+        '#type' => 'textfield',
+        '#default_value' => $browser_langcode,
+        '#size' => 20,
+      ),
+      'drupal_langcode' => array(
+        '#type' => 'textfield',
+        '#default_value' => $drupal_langcode,
+        '#size' => 20,
+      ),
+    );
+  }
+
+  // Add empty row
+  $form['mappings']['_new'] = array(
+    'browser_langcode' => array(
+      '#type' => 'textfield',
+      '#default_value' => '',
+      '#size' => 20,
+    ),
+    'drupal_langcode' => array(
+      '#type' => 'textfield',
+      '#default_value' => '',
+      '#size' => 20,
+    ),
+  );
+
+  $form_state['redirect'] = 'admin/config/regional/language/detection';
+
+  $form['actions']['#type'] = 'actions';
+  $form['actions']['submit'] = array(
+    '#type' => 'submit',
+    '#value' => t('Save configuration'),
+  );
+
+  return $form;
+}
+
+/**
+ * Theme browser configuration form as table.
+ */
+function theme_language_negotiation_configure_browser_form_table($variables) {
+  $form = $variables['form'];
+  $rows = array();
+  $link_attributes = array(
+    'attributes' => array(
+      'class' => array('image-style-link'),
+    ),
+  );
+  foreach (element_children($form, TRUE) as $key) {
+    $row = array();
+    $row[] = drupal_render($form[$key]['browser_langcode']);
+    $row[] = drupal_render($form[$key]['drupal_langcode']);
+
+    if ($key != '_new') {
+      $row[] = l(t('Delete'), 'admin/config/regional/language/detection/browser/delete/' . $key, $link_attributes);
+    }
+    else {
+      $row[] = '';
+    }
+    $rows[] = array(
+      'data' => $row,
+    );
+  }
+
+  $header = array(
+    t('Browser language code'),
+    t('Drupal language code'),
+    t('Operations'),
+  );
+
+  $output = theme('table', array('header' => $header, 'rows' => $rows, 'attributes' => array('id' => 'lang-neg-browser')));
+
+  return $output;
+}
+
+/**
+ * Browser language negotiation form validation.
+ */
+function language_negotiation_configure_browser_form_validate($form, &$form_state) {
+  $mappings = $form_state['values']['mappings'];
+  $unique_values = array();
+  foreach ($mappings as $key => $data) {
+    if ($key == '_new') {
+      if (!empty($data['browser_langcode']) && !empty($data['drupal_langcode'])) {
+        // Make sure browser_langcode is unique
+        if (array_key_exists($data['browser_langcode'], $unique_values)) {
+          form_set_error('mappings][' . $key . '][browser_langcode', 'Browser language codes must be unique.');
+        }
+        elseif (preg_match('/[^a-z\-]/', $data['browser_langcode'])) {
+          form_set_error('mappings][' . $key . '][browser_langcode', 'Browser language codes can only contain lowercase letters and a hyphen(-).');
+        }
+        elseif (preg_match('/[^a-z\-]/', $data['drupal_langcode'])) {
+          form_set_error('mappings][' . $key . '][drupal_langcode', 'Drupal language codes can only contain lowercase letters and a hyphen(-).');
+        }
+        $unique_values[$data['browser_langcode']] = $data['drupal_langcode'];
+      }
+    }
+    else {
+      if (!empty($data['browser_langcode']) && !empty($data['drupal_langcode'])) {
+        // Make sure browser_langcode is unique
+        if (array_key_exists($data['browser_langcode'], $unique_values)) {
+          form_set_error('mappings][' . $key . '][browser_langcode', 'Browser language codes must be unique.');
+        }
+        elseif (preg_match('/[^a-z\-]/', $data['browser_langcode'])) {
+          form_set_error('mappings][' . $key . '][browser_langcode', 'Browser language codes can only contain lowercase letters and a hyphen(-).');
+        }
+        elseif (preg_match('/[^a-z\-]/', $data['drupal_langcode'])) {
+          form_set_error('mappings][' . $key . '][drupal_langcode', 'Drupal language codes can only contain lowercase letters and a hyphen(-).');
+        }
+        $unique_values[$data['browser_langcode']] = $data['drupal_langcode'];
+      }
+      else {
+        if (empty($data['browser_langcode'])) {
+          form_set_error('mappings][' . $key . '][browser_langcode', 'Browser language code cannot be blank.');
+        }
+        if (empty($data['drupal_langcode'])) {
+          form_set_error('mappings][' . $key . '][drupal_langcode', 'Drupal language code cannot be blank.');
+        }
+      }
+    }
+  }
+  $form_state['mappings'] = $unique_values;
+}
+
+/**
+ * Browser language negotiation form submit.
+ */
+function language_negotiation_configure_browser_form_submit($form, &$form_state) {
+  $mappings = $form_state['mappings'];
+  if (!empty($mappings)) {
+    language_set_mappings($mappings);
+  }
+}
+
+/**
+ * Delete a language mapping form.
+ */
+function language_negotiation_configure_browser_delete_form($form, &$form_state, $browser_langcode) {
+  $form_state['browser_langcode'] = $browser_langcode;
+  $question = t('Are you sure you want to delete %browser_langcode', array(
+    '%browser_langcode' => $browser_langcode,
+  ));
+  $path = 'admin/config/regional/language/detection/browser';
+  return confirm_form($form, $question, $path, '');
+}
+
+/**
+ * Delete a language mapping submit.
+ */
+function language_negotiation_configure_browser_delete_form_submit($form, &$form_state) {
+  $browser_langcode = $form_state['browser_langcode'];
+  $mappings = language_get_mappings();
+  if (array_key_exists($browser_langcode, $mappings)) {
+    unset($mappings[$browser_langcode]);
+    language_set_mappings($mappings);
+  }
+  $form_state['redirect'] = 'admin/config/regional/language/detection/browser';
+}
diff --git a/core/modules/language/language.module b/core/modules/language/language.module
index e7d3e2b..4e16ba7 100644
--- a/core/modules/language/language.module
+++ b/core/modules/language/language.module
@@ -116,6 +116,21 @@ function language_menu() {
     'file' => 'language.admin.inc',
     'type' => MENU_VISIBLE_IN_BREADCRUMB,
   );
+  $items['admin/config/regional/language/detection/browser'] = array(
+    'title' => 'Browser language detection configuration',
+    'page callback' => 'drupal_get_form',
+    'page arguments' => array('language_negotiation_configure_browser_form'),
+    'access arguments' => array('administer languages'),
+    'file' => 'language.admin.inc',
+    'type' => MENU_VISIBLE_IN_BREADCRUMB,
+  );
+  $items['admin/config/regional/language/detection/browser/delete/%'] = array(
+    'title' => 'Delete language mapping',
+    'page arguments' => array('language_negotiation_configure_browser_delete_form', 7),
+    'type' => MENU_CALLBACK,
+    'access arguments' => array('administer languages'),
+    'file' => 'language.admin.inc',
+  );
 
   return $items;
 }
@@ -154,6 +169,10 @@ function language_theme() {
     'language_negotiation_configure_form' => array(
       'render element' => 'form',
     ),
+    'language_negotiation_configure_browser_form_table' => array(
+      'render element' => 'form',
+      'file' => 'language.admin.inc',
+    ),
   );
 }
 
@@ -391,6 +410,7 @@ function language_language_negotiation_info() {
     'cache' => 0,
     'name' => t('Browser'),
     'description' => t("Language from the browser's language settings."),
+    'config' => 'admin/config/regional/language/detection/browser',
   );
 
   $negotiation_info[LANGUAGE_NEGOTIATION_INTERFACE] = array(
@@ -598,8 +618,7 @@ function language_url_outbound_alter(&$path, &$options, $original_path) {
 }
 
 /**
- * Returns default language mappings.
- * @todo: How can this be overridden?
+ * Returns language mappings.
  */
 function language_get_mappings() {
   $config = config('language.mappings');
@@ -607,4 +626,13 @@ function language_get_mappings() {
     return FALSE;
   }
   return $config->get();
+}
+
+/**
+ * Stores language mappings.
+ */
+function language_set_mappings($mappings) {
+  $config = config('language.mappings');
+  $config->setData($mappings);
+  $config->save();
 }
\ No newline at end of file