diff --git a/src/Symfony/Component/Config/Definition/EnumNode.php b/src/Symfony/Component/Config/Definition/EnumNode.php
index e8821cf51a6e6..7fc8bf1699f86 100644
--- a/src/Symfony/Component/Config/Definition/EnumNode.php
+++ b/src/Symfony/Component/Config/Definition/EnumNode.php
@@ -22,7 +22,7 @@ class EnumNode extends ScalarNode
 {
     private $values;
 
-    public function __construct(string $name, NodeInterface $parent = null, array $values = array())
+    public function __construct(?string $name, NodeInterface $parent = null, array $values = array())
     {
         $values = array_unique($values);
         if (empty($values)) {
diff --git a/src/Symfony/Component/Config/Tests/Definition/EnumNodeTest.php b/src/Symfony/Component/Config/Tests/Definition/EnumNodeTest.php
index e3e7ef05946fc..48468db2604c0 100644
--- a/src/Symfony/Component/Config/Tests/Definition/EnumNodeTest.php
+++ b/src/Symfony/Component/Config/Tests/Definition/EnumNodeTest.php
@@ -43,6 +43,12 @@ public function testConstructionWithOneDistinctValue()
         $this->assertSame('foo', $node->finalize('foo'));
     }
 
+    public function testConstructionWithNullName()
+    {
+        $node = new EnumNode(null, null, array('foo'));
+        $this->assertSame('foo', $node->finalize('foo'));
+    }
+
     /**
      * @expectedException \Symfony\Component\Config\Definition\Exception\InvalidConfigurationException
      * @expectedExceptionMessage The value "foobar" is not allowed for path "foo". Permissible values: "foo", "bar"