diff --git a/core/modules/system/src/Controller/DbUpdateController.php b/core/modules/system/src/Controller/DbUpdateController.php
index ba5d75c..562e8d9 100644
--- a/core/modules/system/src/Controller/DbUpdateController.php
+++ b/core/modules/system/src/Controller/DbUpdateController.php
@@ -552,6 +552,7 @@ protected function triggerBatch(Request $request) {
     }
     if (empty($_SESSION['maintenance_mode'])) {
       $this->state->set('system.maintenance_mode', TRUE);
+      $_SESSION['maintenance_mode'] = TRUE;
     }
 
     $operations = array();
@@ -631,6 +632,10 @@ public static function batchFinished($success, $results, $operations) {
     // previously in maintenance mode.
     if (isset($_SESSION['maintenance_mode'])) {
       \Drupal::state()->set('system.maintenance_mode', FALSE);
+
+      //Clears the message queue to remove "Operating in maintenance mode" message.
+      drupal_get_messages("status");
+
       unset($_SESSION['maintenance_mode']);
     }
   }