diff --git a/includes/update.inc b/includes/update.inc
index 496b824c20e6efadba4bb47483797728af5e7ea9..958e2477f20df2a7309418ef7c841bac302a3de1 100644
--- a/includes/update.inc
+++ b/includes/update.inc
@@ -696,12 +696,19 @@ function update_fix_d7_requirements() {
       db_add_field('locales_source', 'context', array('type' => 'varchar', 'length' => 255, 'not null' => TRUE, 'default' => '', 'description' => 'The context this string applies to.'));
     }
 
-    // Rename 'site_offline_message' variable to 'maintenance_mode_message'.
+    // Rename 'site_offline_message' variable to 'maintenance_mode_message'
+    // and 'site_offline' variable to 'maintenance_mode'.
     // Old variable is removed in update for system.module, see
     // system_update_7036().
     if ($message = variable_get('site_offline_message', NULL)) {
       variable_set('maintenance_mode_message', $message);
     }
+    // Old variable is removed in update for system.module, see
+    // system_update_7069().
+    $site_offline = variable_get('site_offline', -1);
+    if ($site_offline != -1) {
+      variable_set('maintenance_mode', $site_offline);
+    }
 
     // Add ssid column and index.
     db_add_field('sessions', 'ssid', array('description' => "Secure session ID. The value is generated by Drupal's session handlers.", 'type' => 'varchar', 'length' => 128, 'not null' => TRUE, 'default' => ''));
diff --git a/modules/system/system.install b/modules/system/system.install
index 01924300a3b9d2fba1c2327caf6d97f1a222ef66..22cb59020ec5dc62b92a6270e196c4f5d834e988 100644
--- a/modules/system/system.install
+++ b/modules/system/system.install
@@ -2964,6 +2964,15 @@ function system_update_7068() {
   db_change_field('url_alias', 'language', 'language', $spec);
 }
 
+/**
+ * Remove the obsolete 'site_offline' variable.
+ *
+ * @see update_fix_d7_requirements()
+ */
+function system_update_7069() {
+  variable_del('site_offline');
+}
+
 /**
  * @} End of "defgroup updates-6.x-to-7.x"
  * The next series of updates should start at 8000.