diff --git a/core/includes/theme.maintenance.inc b/core/includes/theme.maintenance.inc
index 4c8023e..c860c6d 100644
--- a/core/includes/theme.maintenance.inc
+++ b/core/includes/theme.maintenance.inc
@@ -45,19 +45,21 @@ function _drupal_maintenance_theme() {
     }
 
     // We use the default theme as the maintenance theme. If a default theme
-    // isn't specified in the database or in settings.php, we use Bartik.
+    // isn't specified in config or in settings.php, we use Bartik.
     // @todo Should use the actual default theme configured, but that depends on
     //   configuration being available while possibly not having a working
     //   database connection (yet). And only if that fails, should fall back to
     //   Stark otherwise. Since there is no low-level access to configuration
     //   currently, we only consult settings.php and fall back to Bartik
     //   otherwise, as it looks generic enough and way more user-friendly.
-    if (($config = \Drupal::config('system.theme')) && is_object($config)) {
-      $custom_theme = $config->get('default');
-    }
-    else  {
+    if (!$custom_theme = settings()->get('maintenance_theme', '')) {
       // A broken install might not return an object.
-      $custom_theme = settings()->get('maintenance_theme', 'bartik');
+      if (($config = \Drupal::config('system.theme')) && is_object($config)) {
+        $custom_theme = $config->get('default');
+      }
+    }
+    if (!$custom_theme) {
+      $custom_theme = 'bartik';
     }
   }