diff --git a/lib/outputrenderers.php b/lib/outputrenderers.php
index 1dc80ca4512..d7e90f33536 100644
--- a/lib/outputrenderers.php
+++ b/lib/outputrenderers.php
@@ -78,7 +78,7 @@ class renderer_base {
     /**
      * @var array $templatecache The mustache template cache.
      */
-    protected $templatecache = array();
+    protected $templatecache = [];
 
     /**
      * Return an instance of the mustache class.