diff --git a/Tests/Twig/Extension/PhoneNumberHelperExtensionTest.php b/Tests/Twig/Extension/PhoneNumberHelperExtensionTest.php
index a6e0daf2..03ce5ead 100644
--- a/Tests/Twig/Extension/PhoneNumberHelperExtensionTest.php
+++ b/Tests/Twig/Extension/PhoneNumberHelperExtensionTest.php
@@ -11,10 +11,8 @@
 
 namespace Misd\PhoneNumberBundle\Tests\Twig\Extension;
 
-
 use Misd\PhoneNumberBundle\Twig\Extension\PhoneNumberHelperExtension;
 
-
 /**
  * Phone number helper Twig extension test.
  */
@@ -41,7 +39,7 @@ protected function setUp()
 
     public function testConstructor()
     {
-        $this->assertInstanceOf('Twig_Extension', $this->extension);
+        $this->assertInstanceOf('Twig\Extension\AbstractExtension', $this->extension);
     }
 
     public function testGetFunctions()
@@ -49,7 +47,7 @@ public function testGetFunctions()
         $functions = $this->extension->getFunctions();
 
         $this->assertCount(2, $functions);
-        $this->assertInstanceOf('Twig_SimpleFunction', $functions[0]);
+        $this->assertInstanceOf('Twig\TwigFunction', $functions[0]);
         $this->assertSame('phone_number_format', $functions[0]->getName());
 
         $callable = $functions[0]->getCallable();
@@ -57,7 +55,7 @@ public function testGetFunctions()
         $this->assertSame($this->helper, $callable[0]);
         $this->assertSame('format', $callable[1]);
 
-        $this->assertInstanceOf('Twig_SimpleFunction', $functions[1]);
+        $this->assertInstanceOf('Twig\TwigFunction', $functions[1]);
         $this->assertSame('phone_number_is_type', $functions[1]->getName());
 
         $callable = $functions[1]->getCallable();
@@ -71,7 +69,7 @@ public function testGetFilters()
         $filters = $this->extension->getFilters();
 
         $this->assertCount(1, $filters);
-        $this->assertInstanceOf('Twig_SimpleFilter', $filters[0]);
+        $this->assertInstanceOf('Twig\TwigFilter', $filters[0]);
         $this->assertSame('phone_number_format', $filters[0]->getName());
 
         $callable = $filters[0]->getCallable();
@@ -85,7 +83,7 @@ public function testGetTests()
         $tests = $this->extension->getTests();
 
         $this->assertCount(1, $tests);
-        $this->assertInstanceOf('Twig_SimpleTest', $tests[0]);
+        $this->assertInstanceOf('Twig\TwigTest', $tests[0]);
         $this->assertSame('phone_number_of_type', $tests[0]->getName());
 
         $callable = $tests[0]->getCallable();
diff --git a/Twig/Extension/PhoneNumberHelperExtension.php b/Twig/Extension/PhoneNumberHelperExtension.php
index fdccc101..5bbfa78f 100644
--- a/Twig/Extension/PhoneNumberHelperExtension.php
+++ b/Twig/Extension/PhoneNumberHelperExtension.php
@@ -12,11 +12,15 @@
 namespace Misd\PhoneNumberBundle\Twig\Extension;
 
 use Misd\PhoneNumberBundle\Templating\Helper\PhoneNumberHelper;
+use Twig\Extension\AbstractExtension;
+use Twig\TwigFilter;
+use Twig\TwigFunction;
+use Twig\TwigTest;
 
 /**
  * Phone number helper Twig extension.
  */
-class PhoneNumberHelperExtension extends \Twig_Extension
+class PhoneNumberHelperExtension extends AbstractExtension
 {
     /**
      * Phone number helper.
@@ -41,8 +45,8 @@ public function __construct(PhoneNumberHelper $helper)
     public function getFunctions()
     {
         return array(
-            new \Twig_SimpleFunction('phone_number_format', array($this->helper, 'format'), array('deprecated' => '1.2')),
-            new \Twig_SimpleFunction('phone_number_is_type', array($this->helper, 'isType'), array('deprecated' => '1.2')),
+            new TwigFunction('phone_number_format', array($this->helper, 'format'), array('deprecated' => '1.2')),
+            new TwigFunction('phone_number_is_type', array($this->helper, 'isType'), array('deprecated' => '1.2')),
         );
     }
 
@@ -52,7 +56,7 @@ public function getFunctions()
     public function getFilters()
     {
         return array(
-            new \Twig_SimpleFilter('phone_number_format', array($this->helper, 'format')),
+            new TwigFilter('phone_number_format', array($this->helper, 'format')),
         );
     }
 
@@ -62,7 +66,7 @@ public function getFilters()
     public function getTests()
     {
         return array(
-            new \Twig_SimpleTest('phone_number_of_type', array($this->helper, 'isType')),
+            new TwigTest('phone_number_of_type', array($this->helper, 'isType')),
         );
     }
 
diff --git a/composer.json b/composer.json
index 3ef12f77..36dc5193 100644
--- a/composer.json
+++ b/composer.json
@@ -21,10 +21,11 @@
         "symfony/serializer": "~2.7|~3.1|~4.0",
         "symfony/templating": "~2.7|~3.0|~4.0",
         "symfony/twig-bundle": "~2.7|~3.0|~4.0",
-        "symfony/validator": "~2.7|~3.0|~4.0"
+        "symfony/validator": "~2.7|~3.0|~4.0",
+        "symfony/intl": "~2.7|~3.0|~4.0"
     },
     "conflict": {
-        "twig/twig": "<1.12.0"
+        "twig/twig": "<1.34.0"
     },
     "suggest": {
         "doctrine/doctrine-bundle": "Add a DBAL mapping type",