diff --git a/core/includes/theme.maintenance.inc b/core/includes/theme.maintenance.inc
index b6b9093..101328a 100644
--- a/core/includes/theme.maintenance.inc
+++ b/core/includes/theme.maintenance.inc
@@ -34,7 +34,7 @@ function _drupal_maintenance_theme() {
 
   // Install and update pages are treated differently to prevent theming overrides.
   if (defined('MAINTENANCE_MODE') && (MAINTENANCE_MODE == 'install' || MAINTENANCE_MODE == 'update')) {
-    $custom_theme = isset($conf['system.theme']['maintenance']) ?: 'seven';
+    $custom_theme = isset($conf['system.theme']['maintenance']) ? $conf['system.theme']['maintenance'] : 'seven';
   }
   else {
     // The bootstrap was not complete. So we are operating in a crippled
diff --git a/sites/default/default.settings.php b/sites/default/default.settings.php
index d7f25e8..a7e6103 100644
--- a/sites/default/default.settings.php
+++ b/sites/default/default.settings.php
@@ -576,7 +576,7 @@
 /**
  * A custom theme can be set for the offline page. This applies when the site
  * is explicitly set to maintenance mode through the administration page or when
- * the database is inactive due to an error. It can be set through the
+ * the database is inactive due to an error. It can be set in
  * $conf['system.theme']['maintenance']. The template file should also be copied
  * into the theme. It is located inside
  * 'core/modules/system/templates/maintenance-page.html.twig.