diff --git a/src/Vuforia/Vuforia.php b/src/Vuforia/Vuforia.php
index 97ec7b8..cc70395 100644
--- a/src/Vuforia/Vuforia.php
+++ b/src/Vuforia/Vuforia.php
@@ -44,7 +44,7 @@ class Vuforia
     /**
      * @var Request[]
      */
-    private $request_instances = [];
+    private $request_instances = array();
 
     /**
      * @var Vuforia