diff --git a/core/modules/views/src/Plugin/views/field/FieldPluginBase.php b/core/modules/views/src/Plugin/views/field/FieldPluginBase.php
index 067e324..bdb44fa 100644
--- a/core/modules/views/src/Plugin/views/field/FieldPluginBase.php
+++ b/core/modules/views/src/Plugin/views/field/FieldPluginBase.php
@@ -106,7 +106,7 @@
    *
    * @var int|NULL
    */
-  public $lastRenderIndex;
+  protected $lastRenderIndex;
 
   /**
    * {@inheritdoc}