Index: captcha.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/captcha/captcha.module,v
retrieving revision 1.103.2.9
diff -u -p -r1.103.2.9 captcha.module
--- captcha.module	5 Jul 2010 21:37:21 -0000	1.103.2.9
+++ captcha.module	19 Oct 2010 16:24:06 -0000
@@ -651,6 +651,7 @@ function captcha_captcha($op, $captcha_t
           '#size' => 4,
           '#maxlength' => 2,
           '#required' => TRUE,
+          '#attributes' => array('autocomplete' => 'off'),
         );
         return $result;
       }
Index: image_captcha/image_captcha.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/captcha/image_captcha/image_captcha.module,v
retrieving revision 1.33.2.1
diff -u -p -r1.33.2.1 image_captcha.module
--- image_captcha/image_captcha.module	16 Mar 2010 21:09:17 -0000	1.33.2.1
+++ image_captcha/image_captcha.module	19 Oct 2010 16:24:07 -0000
@@ -230,6 +230,7 @@ function image_captcha_captcha($op, $cap
           '#weight' => 0,
           '#required' => TRUE,
           '#size' => 15,
+          '#attributes' => array('autocomplete' => 'off'),
         );
 
         // Handle the case insensitive validation option combined with ignoring spaces.