diff --git a/application/forms/Config/Authentication/ExternalBackendForm.php b/application/forms/Config/Authentication/ExternalBackendForm.php
index e25661596..86087eb66 100644
--- a/application/forms/Config/Authentication/ExternalBackendForm.php
+++ b/application/forms/Config/Authentication/ExternalBackendForm.php
@@ -53,7 +53,7 @@ class ExternalBackendForm extends Form
             return @preg_match($value, '') !== false;
         });
         $callbackValidator->setMessage(
-            $this->translate('"%value%" is not a valid regular expression'),
+            $this->translate('"%value%" is not a valid regular expression.'),
             Zend_Validate_Callback::INVALID_VALUE
         );
         $this->addElement(
@@ -62,9 +62,10 @@ class ExternalBackendForm extends Form
             array(
                 'label'         => $this->translate('Filter Pattern'),
                 'description'   => $this->translate(
-                    'The regular expression to use to strip specific parts off from usernames.'
-                    . ' Leave empty if you do not want to strip off anything'
+                    'The filter to use to strip specific parts off from usernames.'
+                    . ' Leave empty if you do not want to strip off anything.'
                 ),
+                'requirement'   => $this->translate('The filter pattern must be a valid regular expression.'),
                 'validators'    => array($callbackValidator)
             )
         );
diff --git a/application/forms/Config/General/LoggingConfigForm.php b/application/forms/Config/General/LoggingConfigForm.php
index 1c4e090c4..bd62f4490 100644
--- a/application/forms/Config/General/LoggingConfigForm.php
+++ b/application/forms/Config/General/LoggingConfigForm.php
@@ -66,6 +66,7 @@ class LoggingConfigForm extends Form
                     'description'   => $this->translate(
                         'The name of the application by which to prefix syslog messages.'
                     ),
+                    'requirement'   => $this->translate('The application prefix must not contain whitespace.'),
                     'value'         => 'icingaweb2',
                     'validators'    => array(
                         array(
diff --git a/application/forms/Config/Resource/FileResourceForm.php b/application/forms/Config/Resource/FileResourceForm.php
index b1bb0c6ae..184a5c18a 100644
--- a/application/forms/Config/Resource/FileResourceForm.php
+++ b/application/forms/Config/Resource/FileResourceForm.php
@@ -3,6 +3,7 @@
 
 namespace Icinga\Forms\Config\Resource;
 
+use Zend_Validate_Callback;
 use Icinga\Web\Form;
 
 /**
@@ -42,13 +43,22 @@ class FileResourceForm extends Form
                 'validators'    => array('ReadablePathValidator')
             )
         );
+        $callbackValidator = new Zend_Validate_Callback(function ($value) {
+            return @preg_match($value, '') !== false;
+        });
+        $callbackValidator->setMessage(
+            $this->translate('"%value%" is not a valid regular expression.'),
+            Zend_Validate_Callback::INVALID_VALUE
+        );
         $this->addElement(
             'text',
             'fields',
             array(
                 'required'      => true,
                 'label'         => $this->translate('Pattern'),
-                'description'   => $this->translate('The regular expression by which to identify columns')
+                'description'   => $this->translate('The pattern by which to identify columns.'),
+                'requirement'   => $this->translate('The column pattern must be a valid regular expression.'),
+                'validators'    => array($callbackValidator)
             )
         );