diff --git fullcalendar_plugin_display_page.inc fullcalendar_plugin_display_page.inc
index 6f76dda..03b8c05 100644
--- fullcalendar_plugin_display_page.inc
+++ fullcalendar_plugin_display_page.inc
@@ -21,7 +21,12 @@ class fullcalendar_plugin_display_page extends views_plugin_display_page {
   function validate() {
     $errors = parent::validate();
 
-    $field_options = $this->display->handler->get_field_labels();
+    // Get the real fields used.
+    $field_options = array();
+    foreach ($this->get_handlers('field') as $key => $value) {
+      $field_options[$key] = $value->definition['field_name'];
+    }
+
     $date_fields = fullcalendar_date_fields($field_options);
 
     if (empty($date_fields)) {