diff --git a/application/controllers/SelfServiceController.php b/application/controllers/SelfServiceController.php
index 5d4393b5..b58e3014 100644
--- a/application/controllers/SelfServiceController.php
+++ b/application/controllers/SelfServiceController.php
@@ -79,16 +79,22 @@ class SelfServiceController extends ActionController
             } else {
                 $error = implode('; ', $form->getErrorMessages());
                 if ($error === '') {
-                    foreach ($form->getErrors() as $elName => $errors) {
-                        if (in_array('isEmpty', $errors)) {
+                    if ($form->isMissingRequiredFields()) {
+                        $fields = $form->listMissingRequiredFields();
+                        if (count($fields) === 1) {
                             $this->sendPowerShellError(
-                                sprintf("%s is required", $elName),
+                                sprintf("%s is required", $fields[0]),
                                 400
                             );
-                            return;
                         } else {
-                            $this->sendPowerShellError('An unknown error ocurred', 500);
+                            $this->sendPowerShellError(
+                                sprintf("Missing parameters: %s", implode(', ', $fields)),
+                                400
+                            );
                         }
+                        return;
+                    } else {
+                        $this->sendPowerShellError('An unknown error ocurred', 500);
                     }
                 } else {
                     $this->sendPowerShellError($error, 400);
@@ -171,13 +177,12 @@ class SelfServiceController extends ActionController
      */
     protected function sendPowerShellError($error, $code)
     {
-        $this->getResponse()->setHttpResponseCode($code);
         if ($this->getRequest()->getHeader('X-Director-Accept') === 'text/plain') {
+            $this->getResponse()->setHttpResponseCode($code);
             echo "ERROR: $error";
         } else {
-            $this->sendJsonError($this->getResponse(), $error);
+            $this->sendJsonError($this->getResponse(), $error, $code);
         }
-        exit;
     }
 
     /**
diff --git a/application/forms/IcingaHostSelfServiceForm.php b/application/forms/IcingaHostSelfServiceForm.php
index ded96a99..1e05b963 100644
--- a/application/forms/IcingaHostSelfServiceForm.php
+++ b/application/forms/IcingaHostSelfServiceForm.php
@@ -83,6 +83,23 @@ class IcingaHostSelfServiceForm extends DirectorForm
         return $this->template;
     }
 
+    public function listMissingRequiredFields()
+    {
+        $result = [];
+        foreach ($this->getElements() as $element) {
+            if (in_array('isEmpty', $element->getErrors())) {
+                $result[] = $element->getName();
+            }
+        }
+
+        return $result;
+    }
+
+    public function isMissingRequiredFields()
+    {
+        return count($this->listMissingRequiredFields()) > 0;
+    }
+
     public function onSuccess()
     {
         $db = $this->getDb();