diff --git a/src/Cache/RecordingCachePool.php b/src/Cache/RecordingCachePool.php
index 8ba3e1a..e0875f1 100644
--- a/src/Cache/RecordingCachePool.php
+++ b/src/Cache/RecordingCachePool.php
@@ -57,7 +57,7 @@ protected function addCall($call)
      *
      * @return object
      */
-    private function timeCall($name, array $arguments = null)
+    private function timeCall($name, array $arguments = [])
     {
         $start  = microtime(true);
         $result = call_user_func_array([$this->cachePool, $name], $arguments);