diff --git a/framework/web/widgets/captcha/CCaptcha.php b/framework/web/widgets/captcha/CCaptcha.php
index <HASH>..<HASH> 100644
--- a/framework/web/widgets/captcha/CCaptcha.php
+++ b/framework/web/widgets/captcha/CCaptcha.php
@@ -27,6 +27,9 @@
  * A {@link CCaptchaValidator} may be used to validate that the user enters
  * a verification code matching the code displayed in the CAPTCHA image.
  *
+ * When combining CCaptcha with CActiveForm or CForm, make sure ajaxValidation is disabled. Performing ajax validation causes
+ * your Captcha to be refreshed, rendering the code invalid on the next validation attempt.
+ *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @package system.web.widgets.captcha
  * @since 1.0
Add documentation explaining you cannot use ajaxValidation with CCaptcha