diff --git a/Form/ChoiceLoader/PostalCodeChoiceLoader.php b/Form/ChoiceLoader/PostalCodeChoiceLoader.php
index 4b52ba38c..027c05e4a 100644
--- a/Form/ChoiceLoader/PostalCodeChoiceLoader.php
+++ b/Form/ChoiceLoader/PostalCodeChoiceLoader.php
@@ -47,7 +47,7 @@ class PostalCodeChoiceLoader implements ChoiceLoaderInterface
     {
         $list = new \Symfony\Component\Form\ChoiceList\ArrayChoiceList(
             $this->lazyLoadedPostalCodes, 
-            function(PostalCode $pc) use ($value) {
+            function(PostalCode $pc = null) use ($value) {
                 return \call_user_func($value, $pc);
             });