diff -u b/core/modules/search/search.module b/core/modules/search/search.module
--- b/core/modules/search/search.module
+++ b/core/modules/search/search.module
@@ -110,7 +110,7 @@
  * Implements hook_theme_suggestions_HOOK().
  */
 function search_theme_suggestions_search_result(array $variables) {
-  return array('search_result__' . $variables['plugin_id']);
+  return ['search_result__' . $variables['plugin_id']];
 }
 
 /**
diff -u b/core/modules/views_ui/views_ui.module b/core/modules/views_ui/views_ui.module
--- b/core/modules/views_ui/views_ui.module
+++ b/core/modules/views_ui/views_ui.module
@@ -160,7 +160,7 @@
  * Implements hook_theme_suggestions_HOOK().
  */
 function views_ui_theme_suggestions_views_ui_view_preview_section(array $variables) {
-  return array('views_ui_view_preview_section__' . $variables['section']);
+  return ['views_ui_view_preview_section__' . $variables['section']];
 }
 
 /**