diff --git a/src/Composer/IO/NullIO.php b/src/Composer/IO/NullIO.php
new file mode 100644
index 000000000..4d854b534
--- /dev/null
+++ b/src/Composer/IO/NullIO.php
@@ -0,0 +1,122 @@
+<?php
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\IO;
+
+/**
+ * IOInterface that is not interactive and never writes the output
+ *
+ * @author Christophe Coevoet <stof@notk.org>
+ */
+class NullIO implements IOInterface
+{
+    /**
+     * {@inheritDoc}
+     */
+    public function isInteractive()
+    {
+        return false;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function write($messages, $newline = true)
+    {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function overwrite($messages, $newline = true, $size = 80)
+    {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function ask($question, $default = null)
+    {
+        return $default;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function askConfirmation($question, $default = true)
+    {
+        return $default;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function askAndValidate($question, $validator, $attempts = false, $default = null)
+    {
+        return $default;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function askAndHideAnswer($question)
+    {
+        return null;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getLastUsername()
+    {
+        return null;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getLastPassword()
+    {
+        return null;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getAuthorizations()
+    {
+        return array();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function hasAuthorization($repositoryName)
+    {
+        return false;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getAuthorization($repositoryName)
+    {
+        return array('username' => null, 'password' => null);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function setAuthorization($repositoryName, $username, $password = null)
+    {
+    }
+}