diff --git a/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php b/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
index 2ff7738..81f1099 100644
--- a/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
+++ b/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
@@ -889,7 +889,7 @@ protected function getAllHandlers($only_overrides = FALSE) {
       if ($only_overrides && $this->isDefaulted($handler_type_info['plural'])) {
         continue;
       }
-      $handlers = array_merge($handlers, $this->getHandlers($handler_type));
+      $handlers = array_merge($handlers, array_values($this->getHandlers($handler_type)));
     }
     return $handlers;
   }
@@ -925,7 +925,7 @@ public function calculateDependencies() {
     $this->addDependencies(parent::calculateDependencies());
     // Collect all the dependencies of handlers and plugins. Only calculate
     // their dependencies if they are configured by this display.
-    $plugins = $this->getAllHandlers(TRUE) + $this->getAllPlugins(TRUE);
+    $plugins = array_merge($this->getAllHandlers(TRUE), $this->getAllPlugins(TRUE));
     array_walk($plugins, array($this, 'calculatePluginDependencies'));
 
     return $this->dependencies;