Index: math_captcha/math_captcha.module
===================================================================
--- math_captcha/math_captcha.module	(revision 5335)
+++ math_captcha/math_captcha.module	(working copy)
@@ -41,8 +41,8 @@
     case 'list':
       return array('Math CAPTCHA');
     case 'generate':
-      require_once('math_captcha.challenge.inc');
       if ($captcha_type == 'Math CAPTCHA') {
+        require_once('math_captcha.challenge.inc');
         // get the available challenges
         $challenges = array_filter(_math_captcha_enabled_challenges());
         $challenge = $challenges[array_rand($challenges)];