diff --git a/src/Symfony/Component/Console/Question/ConfirmationQuestion.php b/src/Symfony/Component/Console/Question/ConfirmationQuestion.php
index 150ab27f303be..d871fb8a79b0b 100644
--- a/src/Symfony/Component/Console/Question/ConfirmationQuestion.php
+++ b/src/Symfony/Component/Console/Question/ConfirmationQuestion.php
@@ -53,7 +53,7 @@ private function getDefaultNormalizer()
                 return $answer && $answerIsTrue;
             }
 
-            return !$answer || $answerIsTrue;
+            return '' === $answer || $answerIsTrue;
         };
     }
 }
diff --git a/src/Symfony/Component/Console/Tests/Question/ConfirmationQuestionTest.php b/src/Symfony/Component/Console/Tests/Question/ConfirmationQuestionTest.php
index 12d1bee2ae782..e18566eece08a 100644
--- a/src/Symfony/Component/Console/Tests/Question/ConfirmationQuestionTest.php
+++ b/src/Symfony/Component/Console/Tests/Question/ConfirmationQuestionTest.php
@@ -40,7 +40,7 @@ public function normalizerUsecases()
             ],
             [
                 true,
-                ['n', 'N', 'no', 'NO', 'nO', 'foo', '1'],
+                ['n', 'N', 'no', 'NO', 'nO', 'foo', '1', '0'],
                 false,
                 'When default is true, the normalizer must return false for "%s"',
             ],