1 files changed, 6 insertions, 2 deletions
diff --git a/modules/system/system.module b/modules/system/system.module
index 865eec1f1..3e6954f06 100644
--- a/modules/system/system.module
+++ b/modules/system/system.module
@@ -399,9 +399,13 @@ function system_element_info() {
   );
   $types['select'] = array(
     '#input' => TRUE,
-    '#size' => 0,
+    // In order to be able to determine whether a select list needs an empty
+    // default option, #required has to be NULL by default, as form_builder()
+    // preemptively sets #required to FALSE for all elements.
+    // @see form_process_select()
+    '#required' => NULL,
     '#multiple' => FALSE,
-    '#process' => array('ajax_process_form'),
+    '#process' => array('form_process_select', 'ajax_process_form'),
     '#theme' => 'select',
     '#theme_wrappers' => array('form_element'),
   );