diff --git a/core/modules/views/lib/Drupal/views/Tests/UI/DisplayTest.php b/core/modules/views/lib/Drupal/views/Tests/UI/DisplayTest.php
index f2acf25..786be98 100644
--- a/core/modules/views/lib/Drupal/views/Tests/UI/DisplayTest.php
+++ b/core/modules/views/lib/Drupal/views/Tests/UI/DisplayTest.php
@@ -167,8 +167,8 @@ public function testCloneDisplay() {
     $displays = $view->displayHandlers;
     $this->assertTrue($displays['page_2'], 'The new page display got saved.');
     $this->assertTrue($displays['block_1'], 'The new block display got saved.');
-    $this->assertEqual($displays['page_2'], 'Page 2', 'The new display title got generated as expected.');
-    $this->assertEqual($displays['block_1'], 'Block 1', 'The new display title got generated as expected.');
+    $this->assertEqual($displays['page_2']->display['display_title'], 'Page');
+    $this->assertEqual($displays['block_1']->display['display_title'], 'Block', 'The new display title got generated as expected.');
     $this->assertEqual($displays['block_1']->getOption('title'), $random_title, 'The overridden title option from the display got copied into the clone');
     $this->assertEqual($displays['block_1']->getOption('css_class'), $random_css, 'The overridden css_class option from the display got copied into the clone');
   }
diff --git a/core/modules/views/views_ui/lib/Drupal/views_ui/ViewEditFormController.php b/core/modules/views/views_ui/lib/Drupal/views_ui/ViewEditFormController.php
index 1133b9a..c27575d 100644
--- a/core/modules/views/views_ui/lib/Drupal/views_ui/ViewEditFormController.php
+++ b/core/modules/views/views_ui/lib/Drupal/views_ui/ViewEditFormController.php
@@ -8,6 +8,7 @@
 namespace Drupal\views_ui;
 
 use Drupal\Core\Entity\EntityInterface;
+use Drupal\Component\Utility\NestedArray;
 use Drupal\views\ViewExecutable;
 
 /**
@@ -798,7 +799,7 @@ public function submitCloneDisplayAsType($form, &$form_state) {
     $display_clone = $displays[$display_id];
     unset($display_clone['display_title']);
 
-    $displays[$new_display_id] += $display_clone;
+    $displays[$new_display_id] = NestedArray::mergeDeep($displays[$new_display_id], $display_clone);
     $displays[$new_display_id]['id'] = $new_display_id;
     $view->set('display', $displays);