diff --git a/modules/system/system.admin.inc b/modules/system/system.admin.inc
index cdcc78f..32f8283 100644
--- a/modules/system/system.admin.inc
+++ b/modules/system/system.admin.inc
@@ -2230,11 +2230,26 @@ function system_site_maintenance_mode() {
     '#default_value' => variable_get('maintenance_mode_message', t('@site is currently under maintenance. We should be back shortly. Thank you for your patience.', array('@site' => variable_get('site_name', 'Drupal')))),
     '#description' => t('Message to show visitors when the site is in maintenance mode.')
   );
-
+  
+  $form['#submit'][] = 'system_site_maintenance_mode_form_submit';
+  
   return system_settings_form($form);
 }
 
 /**
+ * Default submit handler for maintenance mode
+ */
+function system_site_maintenance_mode_form_submit($form, &$form_state) {
+  global $user;
+  
+  // Log user who enabled mainenance mode
+  if ($form['maintenance_mode']['#value'] == TRUE) {
+    watchdog('system', 'Maintenance Mode enabled by User - "%user"', array('%user' => $user->name), WATCHDOG_INFO);
+  }
+}
+
+
+/**
  * Form builder; Configure clean URL settings.
  *
  * @ingroup forms