diff --git a/src/Composer/Command/Helper/DialogHelper.php b/src/Composer/Command/Helper/DialogHelper.php
index 674b03800..d08ac1946 100644
--- a/src/Composer/Command/Helper/DialogHelper.php
+++ b/src/Composer/Command/Helper/DialogHelper.php
@@ -28,9 +28,9 @@ class DialogHelper extends BaseDialogHelper
*
* @return string
*/
- public function getQuestion($question, $default, $sep = ':')
+ public function getQuestion($question, $default = null, $sep = ':')
{
- return $default ?
+ return $default !== null ?
sprintf('%s [%s]%s ', $question, $default, $sep) :
sprintf('%s%s ', $question, $sep);
}