diff --git a/lib/Cake/Error/exceptions.php b/lib/Cake/Error/exceptions.php
index 992aacf60..3a788133c 100644
--- a/lib/Cake/Error/exceptions.php
+++ b/lib/Cake/Error/exceptions.php
@@ -63,7 +63,7 @@ class CakeBaseException extends RuntimeException {
  *
  * @package       Cake.Error
  */
-if (!class_exists('HttpException')) {
+if (!class_exists('HttpException', false)) {
 	class HttpException extends CakeBaseException {
 	}
 }