diff --git a/ajax_chain_select.module b/ajax_chain_select.module
index d9188a1..cde6824 100644
--- a/ajax_chain_select.module
+++ b/ajax_chain_select.module
@@ -62,6 +62,7 @@ function ajax_chain_select_element_process($element, &$form_state, $form) {
   );
 
   $chain_select_element[$element_name] = array(
+    '#element_name' => $element_name,
     '#type' => 'fieldset',
     '#tree' => TRUE,
     '#id' => !empty($element['#id']) ? $element['#id'] : drupal_html_id('edit-' . implode('-', $element['#parents'])),
@@ -153,9 +154,14 @@ function ajax_chain_select_element_process($element, &$form_state, $form) {
  * Custom function for ac_select element validate.
  */
 function ajax_chain_select_custom_validate(&$element, &$form_state, $form) {
-  $values = $form_state['values'];
+  // Clean up fields 'dc' and 'dch'.
+  $element_name = $element['#element_name'];
+  unset($form_state['values'][$element_name]['dc']);
+  unset($form_state['values'][$element_name]['dch']);
+
   $data_callback = $element['#data_callback'];
   $config = $element['#config'];
+  $values = $form_state['values'];
 
   $index = 0;
   $levels = array_keys($config);
diff --git a/ajax_chain_select_example/ajax_chain_select_example.module b/ajax_chain_select_example/ajax_chain_select_example.module
index b2ce3ff..61b96a7 100644
--- a/ajax_chain_select_example/ajax_chain_select_example.module
+++ b/ajax_chain_select_example/ajax_chain_select_example.module
@@ -70,8 +70,6 @@ function ajax_chain_select_example_sample_form($form, &$form_state) {
  */
 function ajax_chain_select_example_sample_form_submit($form, &$form_state) {
   $values = $form_state['values']['region'];
-  unset($values['dc']);
-  unset($values['dch']);
   $submitted_values = print_r($values, 1);
   drupal_set_message(t('The form has been successfully submitted with values: <pre>@values</pre>', array('@values' => $submitted_values)));
 }