diff --git a/DependencyInjection/Configuration.php b/DependencyInjection/Configuration.php
index 439baf6..8394647 100644
--- a/DependencyInjection/Configuration.php
+++ b/DependencyInjection/Configuration.php
@@ -4,6 +4,7 @@
 
 use Symfony\Component\Config\Definition\Builder\TreeBuilder;
 use Symfony\Component\Config\Definition\ConfigurationInterface;
+use Symfony\Component\HttpKernel\Kernel;
 
 class Configuration implements ConfigurationInterface
 {
@@ -18,8 +19,13 @@ class Configuration implements ConfigurationInterface
      */
     public function getConfigTreeBuilder()
     {
-        $treeBuilder = new TreeBuilder();
-        $rootNode = $treeBuilder->root('lifo_typeahead');
+        if (Kernel::VERSION_ID < 40000) {
+            $treeBuilder = new TreeBuilder();
+            $rootNode = $treeBuilder->root('lifo_typeahead');
+        } else {
+            $treeBuilder = new TreeBuilder('lifo_typeahead');
+            $rootNode = $treeBuilder->getRootNode();
+        }
 
         $rootNode
             ->children()
diff --git a/DependencyInjection/LifoTypeaheadExtension.php b/DependencyInjection/LifoTypeaheadExtension.php
index 6caecdf..b6f0071 100644
--- a/DependencyInjection/LifoTypeaheadExtension.php
+++ b/DependencyInjection/LifoTypeaheadExtension.php
@@ -83,7 +83,10 @@ protected function configureTwigBundle(ContainerBuilder $container, array $confi
     {
         if ($container->hasExtension('twig')) {
             $resources = array('LifoTypeaheadBundle:Form:typeahead.html.twig');
-            if (Kernel::VERSION_ID >= '20600') {
+            if (Kernel::VERSION_ID >= 40000) {
+                $resources = array('@LifoTypeahead/Form/typeahead.html.twig');
+                $container->prependExtensionConfig('twig', array('form_themes' => $resources));
+            } elseif (Kernel::VERSION_ID >= 20600) {
                 $container->prependExtensionConfig('twig', array('form_themes' => $resources));
             } else {
                 $container->prependExtensionConfig('twig', array('form' => array('resources' => $resources)));
diff --git a/Resources/views/Form/typeahead.html.twig b/Resources/views/Form/typeahead.html.twig
index 0523927..e59939d 100644
--- a/Resources/views/Form/typeahead.html.twig
+++ b/Resources/views/Form/typeahead.html.twig
@@ -1,5 +1,4 @@
 {% block entity_typeahead_widget %}
-{% spaceless %}
     {% set main_full_name, main_id, main_value, main_attr = full_name, id, value, attr %}
 
     {# create visible autocomplete input #}
@@ -41,21 +40,19 @@
         {% set id, full_name = main_id, main_full_name %}
         {{ block('entity_typeahead_multiple_widget') }}
     {% endif %}
-{% endspaceless %}
 {% endblock %}
 
 {% block entity_typeahead_multiple_widget %}
-{% spaceless %}
     <ul id="{{ id }}_list" class="lifo-typeahead-list" {% if 'input_group' in attr and attr.input_group is not empty %}style="display:none"{% endif %}>
-    {% for child in form.vars.data if child is not null %}
-        {{ block('entity_typeahead_list_widget') }}
+    {% for child in form.vars.data %}
+        {% if child is not null %}
+            {{ block('entity_typeahead_list_widget') }}
+        {% endif %}
     {% endfor %}
     </ul>
-{% endspaceless %}
 {% endblock %}
 
 {% block entity_typeahead_list_widget %}
-{% spaceless %}
     {% if simple %}
         {% set _id, _value, _render = child, child, child %}
     {% else %}
@@ -65,5 +62,4 @@
         <input{% if child is not null %} id="{{ id ~ '_' ~ _id }}" name="{{ full_name }}[]" value="{{ _value }}"{% endif %} type="hidden" />
         <a href="" class="lifo-typeahead-item" title="{{ "Click to remove"|trans }}">{{ child is not null ? _render : '' }}</a>
     </li>
-{% endspaceless %}
 {% endblock %}
diff --git a/Twig/Extension/TypeaheadTwigExtension.php b/Twig/Extension/TypeaheadTwigExtension.php
index 85b372d..b593f1a 100644
--- a/Twig/Extension/TypeaheadTwigExtension.php
+++ b/Twig/Extension/TypeaheadTwigExtension.php
@@ -2,12 +2,11 @@
 
 namespace Lifo\TypeaheadBundle\Twig\Extension;
 
-use Assetic\Asset\AssetCollection;
-use Assetic\Asset\StringAsset;
-use Assetic\Filter\Yui\JsCompressorFilter;
 use Lifo\TypeaheadBundle\Form\Type\TypeaheadType;
+use Twig\Extension\AbstractExtension;
+use Twig\TwigFunction;
 
-class TypeaheadTwigExtension extends \Twig_Extension
+class TypeaheadTwigExtension extends AbstractExtension
 {
     public function getName()
     {
@@ -17,7 +16,7 @@ public function getName()
     public function getFunctions()
     {
         return array(
-            new \Twig_SimpleFunction('lifo_typeahead_init', array($this, 'initTypeaheadFunction'), array('needs_environment' => true, 'is_safe' => array('html'))),
+            new TwigFunction('lifo_typeahead_init', array($this, 'initTypeaheadFunction'), array('needs_environment' => true, 'is_safe' => array('html'))),
         );
     }