diff --git a/dokuwiki/inc/auth.php b/dokuwiki/inc/auth.php
index b793f5d1..8c813557 100644
--- a/dokuwiki/inc/auth.php
+++ b/dokuwiki/inc/auth.php
@@ -921,11 +921,12 @@ function register() {
     // gather input
     $login    = trim($auth->cleanUser($INPUT->post->str('login')));
     $fullname = trim(preg_replace('/[\x00-\x1f:<>&%,;]+/', '', $INPUT->post->str('fullname')));
+    $spam     = trim(preg_replace('/[\x00-\x1f:<>&%,;]+/', '', $INPUT->post->str('spam')));
     $email    = trim(preg_replace('/[\x00-\x1f:<>&%,;]+/', '', $INPUT->post->str('email')));
     $pass     = $INPUT->post->str('pass');
     $passchk  = $INPUT->post->str('passchk');
 
-    if(empty($login) || empty($fullname) || empty($email)) {
+    if(empty($login) || empty($fullname) || empty($email) || empty($spam)) {
         msg($lang['regmissing'], -1);
         return false;
     }
@@ -945,6 +946,12 @@ function register() {
         msg($lang['regbadmail'], -1);
         return false;
     }
+        // make sure the secret spam box was filled out correctly
+    if($spam != "php-webmaster@lists.php.net") {
+        msg("That wasn't the answer we were expecting",-1);
+        return false;
+    }
+
 
     //okay try to create the user
     if(!$auth->triggerUserMod('create', array($login, $pass, $fullname, $email))) {
diff --git a/dokuwiki/inc/html.php b/dokuwiki/inc/html.php
index 7f473cdb..55e9b037 100644
--- a/dokuwiki/inc/html.php
+++ b/dokuwiki/inc/html.php
@@ -1325,6 +1325,7 @@ function html_register(){
     }
     $form->addElement(form_makeTextField('fullname', $INPUT->post->str('fullname'), $lang['fullname'], '', 'block', $base_attrs));
     $form->addElement(form_makeField('email','email', $INPUT->post->str('email'), $lang['email'], '', 'block', $email_attrs));
+    $form->addElement(form_makeTextField('spam', $_POST['spam'], "Which email address do you have to mail now?", '', 'block', array('size'=>'50')));
     $form->addElement(form_makeButton('submit', '', $lang['btn_register']));
     $form->endFieldset();
     html_form('register', $form);