diff --git a/src/Symfony/Component/Console/Cursor.php b/src/Symfony/Component/Console/Cursor.php
index 9f8be9649c522..a0225ddf0eda0 100644
--- a/src/Symfony/Component/Console/Cursor.php
+++ b/src/Symfony/Component/Console/Cursor.php
@@ -21,8 +21,16 @@ final class Cursor
     private $output;
     private $input;
 
-    public function __construct(OutputInterface $output, $input = STDIN)
+    public function __construct(OutputInterface $output, $input = null)
     {
+        if (null === $input && !\defined('STDIN')) {
+            throw new \TypeError(sprintf('The second argument of "%s()" must be a resource.', __METHOD__));
+        }
+
+        if (null === $input) {
+            $input = STDIN;
+        }
+
         $this->output = $output;
         $this->input = $input;
     }