diff --git a/core/includes/language.inc b/core/includes/language.inc
index 0892cc4..362e5f8 100644
--- a/core/includes/language.inc
+++ b/core/includes/language.inc
@@ -303,6 +303,7 @@ function language_negotiation_method_enabled($method_id, $type = NULL) {
 function language_negotiation_get_switch_links($type, $path) {
   $links = FALSE;
   $negotiation = variable_get("language_negotiation_$type", array());
+  $language = language_types_initialize($type);
 
   foreach ($negotiation as $method_id => $method) {
     if (isset($method['callbacks']['language_switch'])) {
@@ -313,9 +314,28 @@ function language_negotiation_get_switch_links($type, $path) {
       $callback = $method['callbacks']['language_switch'];
       $result = $callback($type, $path);
 
+      // Add language specific CSS class as well as support for WCAG 2.0's
+      // Language of Parts to add language identifiers
+      // http://www.w3.org/TR/UNDERSTANDING-WCAG20/meaning-other-lang-id.html
+      foreach ($result as $langcode => $link) {
+        $result[$langcode]['attributes']['class'][] = 'language-link-' . $langcode;
+        $result[$langcode]['attributes']['lang'] = $langcode;
+      }
+
       if (!empty($result)) {
         // Allow modules to provide translations for specific links.
         drupal_alter('language_switch_links', $result, $type, $path);
+        // Add links to alternative versions of this content in other
+        // languages to the header to improve SEO
+        foreach($result as $langcode => $link) {
+          if ($langcode != $language->langcode) {
+            drupal_add_html_head_link(array(
+              'rel' => 'alternate',
+              'hreflang' => $langcode,
+              'href' => $langcode  . '/' . $link['href'],
+            ));
+          }
+        }
         $links = (object) array('links' => $result, 'method_id' => $method_id);
         break;
       }
diff --git a/core/modules/language/lib/Drupal/language/Tests/LanguageUILanguageNegotiationTest.php b/core/modules/language/lib/Drupal/language/Tests/LanguageUILanguageNegotiationTest.php
index 02d5139..cadd977 100644
--- a/core/modules/language/lib/Drupal/language/Tests/LanguageUILanguageNegotiationTest.php
+++ b/core/modules/language/lib/Drupal/language/Tests/LanguageUILanguageNegotiationTest.php
@@ -279,7 +279,7 @@ class LanguageUILanguageNegotiationTest extends WebTestBase {
     // Check that the language switcher active link matches the given browser
     // language.
     $args = array(':url' => base_path() . $GLOBALS['script_path'] . $langcode_browser_fallback);
-    $fields = $this->xpath('//div[@id="block-language-language-interface"]//a[@class="language-link active" and starts-with(@href, :url)]', $args);
+    $fields = $this->xpath('//div[@id="block-language-language-interface"]//a[@class="language-link language-link-it active" and starts-with(@href, :url)]', $args);
     $this->assertTrue($fields[0] == $languages[$langcode_browser_fallback]->name, t('The browser language is the URL active language'));
 
     // Check that URLs are rewritten using the given browser language.