diff --git a/ding_provider.reservation.inc b/ding_provider.reservation.inc
index 6d7a7cf..c226b27 100644
--- a/ding_provider.reservation.inc
+++ b/ding_provider.reservation.inc
@@ -250,6 +250,10 @@ class DingProviderReservationExists extends DingProviderReservationUserError {
   public function __construct($message = "", $code = 0) {
     if (empty($message)) {
       $message = t('"You have already reserved "@title".');
+
+      if ($code) {
+        $message .= t('Error message "@code."', array('@code' => $code));
+      }
     }
     parent::__construct($message);
   }
@@ -262,6 +266,10 @@ class DingProviderReservationNotAvailable extends DingProviderReservationUserErr
   public function __construct($message = "", $code = 0) {
     if (empty($message)) {
       $message = t('"@title" is not available for reservation.');
+
+      if ($code) {
+        $message .= t('Error message "@code."', array('@code' => $code));
+      }
     }
     parent::__construct($message);
   }
@@ -274,6 +282,10 @@ class DingProviderReservationNotAllowed extends DingProviderReservationUserError
   public function __construct($message = "", $code = 0) {
     if (empty($message)) {
       $message = t("You're not allowed to reserve \"@title\".");
+
+      if ($code) {
+        $message .= t('Error message "@code."', array('@code' => $code));
+      }
     }
     parent::__construct($message);
   }