diff --git a/Resources/config/services.xml b/Resources/config/services.xml
index a5c3f66..cf8c4d1 100644
--- a/Resources/config/services.xml
+++ b/Resources/config/services.xml
@@ -16,6 +16,7 @@
         <parameter key="jms_i18n_routing.cookie_setting_listener.class">JMS\I18nRoutingBundle\EventListener\CookieSettingListener</parameter>
         
         <parameter key="jms_i18n_routing.route_translation_extractor.class">JMS\I18nRoutingBundle\Translation\RouteTranslationExtractor</parameter>
+        <parameter key="jms_i18n_routing.twig_extension.class">JMS\I18nRoutingBundle\Twig\I18nRoutingExtension</parameter>
     </parameters>
 
     <services>
@@ -37,6 +38,9 @@
             <call method="setRedirectToHost">
                 <argument>%jms_i18n_routing.redirect_to_host%</argument>
             </call>
+            <call method="setLogger">
+                <argument type="service" id="logger" on-invalid="null" />
+            </call>
         </service>
         
         <service id="jms_i18n_routing.locale_choosing_listener" class="%jms_i18n_routing.locale_choosing_listener.class%" public="false">
@@ -69,5 +73,11 @@
             <argument type="service" id="jms_i18n_routing.route_exclusion_strategy" />
             <tag name="jms_translation.extractor" alias="jms_i18n_routing" />
         </service>
+
+        <service id="jms_i18n_routing.twig_extension" class="%jms_i18n_routing.twig_extension.class%" public="false">
+            <argument type="service" id="request_stack" />
+            <argument>%jms_i18n_routing.locales%</argument>
+            <tag name="twig.extension" />
+        </service>
     </services>
 </container>
diff --git a/Resources/views/hreflang.html.twig b/Resources/views/hreflang.html.twig
new file mode 100644
index 0000000..cbabc37
--- /dev/null
+++ b/Resources/views/hreflang.html.twig
@@ -0,0 +1,5 @@
+
+{% for locale in locales %}
+    {% set arr = routeParams|merge({'_locale':locale}) %}
+    <link rel="alternate" hreflang="{{ locale }}" href="{{ url(route, arr) }}" />
+{% endfor %}
diff --git a/Router/I18nLoader.php b/Router/I18nLoader.php
index c6148dd..0e67e84 100644
--- a/Router/I18nLoader.php
+++ b/Router/I18nLoader.php
@@ -63,6 +63,7 @@ public function load(RouteCollection $collection)
                     $catchMultipleRoute = clone $route;
                     $catchMultipleRoute->setPath($pattern);
                     $catchMultipleRoute->setDefault('_locales', $locales);
+                    $catchMultipleRoute->setDefault('localized', true);
                     $i18nCollection->add(implode('_', $locales).I18nLoader::ROUTING_PREFIX.$name, $catchMultipleRoute);
                 }
 
@@ -70,6 +71,7 @@ public function load(RouteCollection $collection)
                     $localeRoute = clone $route;
                     $localeRoute->setPath($pattern);
                     $localeRoute->setDefault('_locale', $locale);
+                    $localeRoute->setDefault('localized', true);
                     $i18nCollection->add($locale.I18nLoader::ROUTING_PREFIX.$name, $localeRoute);
                 }
             }
diff --git a/Router/I18nRouter.php b/Router/I18nRouter.php
index 42dd248..e61181d 100644
--- a/Router/I18nRouter.php
+++ b/Router/I18nRouter.php
@@ -20,6 +20,9 @@
 
 use JMS\I18nRoutingBundle\Exception\NotAcceptableLanguageException;
 
+use Psr\Log\LoggerAwareInterface;
+use Psr\Log\LoggerAwareTrait;
+use Psr\Log\LoggerInterface;
 use Symfony\Component\Routing\Matcher\RequestMatcherInterface;
 use Symfony\Component\Routing\RequestContext;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -33,7 +36,7 @@
  *
  * @author Johannes M. Schmitt <schmittjoh@gmail.com>
  */
-class I18nRouter extends Router
+class I18nRouter extends Router implements LoggerAwareInterface
 {
     private $hostMap = array();
     private $i18nLoaderId;
@@ -140,8 +143,21 @@ public function generate($name, $parameters = array(), $referenceType = self::AB
             // fallback to default behavior
         }
 
-        // use the default behavior if no localized route exists
-        return $generator->generate($name, $parameters, $referenceType);
+        try {
+            // use the default behavior if no localized route exists
+            return $generator->generate($name, $parameters, $referenceType);
+        } catch (\Exception $e) {
+            if ($this->logger) {
+                $this->logger->critical('JMSRouter tried to generate a route', [
+                    'category'=>'routing',
+                    'name'=>$name,
+                    'parameters'=>json_encode($parameters),
+                    'absolute'=>$absolute ? 'true' : 'false',
+                ]);
+            }
+
+            throw $e;
+        }
     }
 
     /**
@@ -290,4 +306,15 @@ private function getRequest()
 
         return $request;
     }
+
+
+    /**
+     * Sets a logger.
+     *
+     * @param LoggerInterface $logger
+     */
+    public function setLogger(LoggerInterface $logger)
+    {
+        $this->logger = $logger;
+    }
 }
diff --git a/Twig/I18nRoutingExtension.php b/Twig/I18nRoutingExtension.php
new file mode 100644
index 0000000..fdde736
--- /dev/null
+++ b/Twig/I18nRoutingExtension.php
@@ -0,0 +1,77 @@
+<?php
+
+namespace JMS\I18nRoutingBundle\Twig;
+
+use Symfony\Component\HttpFoundation\RequestStack;
+
+/**
+ * @author Tobias Nyholm
+ */
+class I18nRoutingExtension extends \Twig_Extension
+{
+    /**
+     * @var RequestStack requestStack
+     */
+    private $requestStack;
+
+    /**
+     * @var array locales
+     */
+    private $locales;
+
+    /**
+     * @param RequestStack $requestStack
+     * @param array        $locales
+     */
+    public function __construct(RequestStack $requestStack, $locales)
+    {
+        $this->requestStack = $requestStack;
+        $this->locales = $locales;
+    }
+
+    public function getFunctions()
+    {
+        return array(
+            new \Twig_SimpleFunction('hreflang', array($this, 'getHreflang'), array(
+                'needs_environment'=>true,
+                'is_safe'=>array('html'),
+                )),
+        );
+    }
+
+    /**
+     * Return HTML with hreflang attributes
+     *
+     * @param \Twig_Environment $env
+     */
+    public function getHreflang(\Twig_Environment $env)
+    {
+        if (null === $request = $this->requestStack->getMasterRequest()) {
+            return;
+        }
+
+        if (null === $routeParams = $request->attributes->get('_route_params')) {
+            return;
+        }
+
+        if (!isset($routeParams['localized']) || !$routeParams['localized']) {
+            return;
+        }
+
+        return $env->render('JMSI18nRoutingBundle::hreflang.html.twig', array(
+            'locales'=>$this->locales,
+            'route'=>$request->attributes->get('_route'),
+            'routeParams'=>$routeParams,
+        ));
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @return string
+     */
+    public function getName()
+    {
+        return 'i18n_routing_extension';
+    }
+}
\ No newline at end of file
diff --git a/composer.json b/composer.json
index be9a7aa..855e0ba 100644
--- a/composer.json
+++ b/composer.json
@@ -16,7 +16,7 @@
         }
     ],
     "require": {
-	"php": ">=5.3.9",
+        "php": ">=5.3.9",
         "symfony/framework-bundle": "~2.3|~3.0"
     },
     "require-dev": {