diff --git a/lib/Paymill/Services/ResponseHandler.php b/lib/Paymill/Services/ResponseHandler.php
old mode 100644
new mode 100755
index f599e19..4cb13d2
--- a/lib/Paymill/Services/ResponseHandler.php
+++ b/lib/Paymill/Services/ResponseHandler.php
@@ -77,6 +77,7 @@ class ResponseHandler
         40401 => "Amount too low or zero.",
         40402 => "Usage field too long.",
         40403 => "Currency not allowed.",
+        40404 => "Refund amount exceeds the possible value",
         40410 => "Invalid shopping cart data.",
         40420 => "Invalid address data.",
         40500 => "Permission error.",
diff --git a/tests/Unit/Paymill/Services/ResponseHandlerTest.php b/tests/Unit/Paymill/Services/ResponseHandlerTest.php
old mode 100644
new mode 100755
index a2bdc06..eead5cc
--- a/tests/Unit/Paymill/Services/ResponseHandlerTest.php
+++ b/tests/Unit/Paymill/Services/ResponseHandlerTest.php
@@ -33,6 +33,7 @@ class ResponseHandlerTest extends PHPUnit_Framework_TestCase
         40401 => "Amount too low or zero.",
         40402 => "Usage field too long.",
         40403 => "Currency not allowed.",
+        40404 => "Refund amount exceeds the possible value",
         50000 => "General problem with backend.",
         50001 => "Country blacklisted.",
         50100 => "Technical error with credit card.",