diff --git a/captcha.module b/captcha.module
index 6b36605e045676e22cd4984c6a442ea38bd10f82..e7996ff4b09ba1a0cd4fc8b32fe82c8ccf836ce8 100644
--- a/captcha.module
+++ b/captcha.module
@@ -269,6 +269,9 @@ function captcha_process($element, $edit, &$form_state, $complete_form) {
     // Store the solution in the #captcha_info array.
     $element['#captcha_info']['solution'] = $captcha['solution'];
 
+    // Make sure we can use a top level form value $form_state['values']['captcha_response'], even if the form has #tree=true.
+    $element['#tree'] = FALSE;
+
   }
 
   return $element;