diff --git a/CRM/Utils/Cache/ArrayCache.php b/CRM/Utils/Cache/ArrayCache.php
index 95ac6d2481ce..2622554330af 100644
--- a/CRM/Utils/Cache/ArrayCache.php
+++ b/CRM/Utils/Cache/ArrayCache.php
@@ -39,7 +39,7 @@ class CRM_Utils_Cache_Arraycache implements CRM_Utils_Cache_Interface {
   /**
    * The cache storage container, an in memory array by default
    */
-  private $_cache;
+  protected $_cache;
 
   /**
    * Constructor.