diff --git a/src/Symfony/Component/Form/Extension/Core/DataTransformer/ChoicesToBooleanArrayTransformer.php b/src/Symfony/Component/Form/Extension/Core/DataTransformer/ChoicesToBooleanArrayTransformer.php
index 715a91e3ff..5ec30926ad 100644
--- a/src/Symfony/Component/Form/Extension/Core/DataTransformer/ChoicesToBooleanArrayTransformer.php
+++ b/src/Symfony/Component/Form/Extension/Core/DataTransformer/ChoicesToBooleanArrayTransformer.php
@@ -107,7 +107,7 @@ class ChoicesToBooleanArrayTransformer implements DataTransformerInterface
         }
 
         if (count($unknown) > 0) {
-            throw new TransformationFailedException('The choices "' . implode('", "', $unknown, $code, $previous) . '" where not found');
+            throw new TransformationFailedException('The choices "' . implode('", "', $unknown) . '" where not found');
         }
 
         return $result;