diff --git a/boot.php b/boot.php
index 0c25dfef3d..e49ffbd221 100644
--- a/boot.php
+++ b/boot.php
@@ -1100,7 +1100,7 @@ class App {
 	}
 
 	function save_timestamp($stamp, $value) {
-		if (!isset($a->config['system']['profiler']) || !$a->config['system']['profiler'])
+		if (!isset($this->config['system']['profiler']) || !$this->config['system']['profiler'])
 			return;
 
 		$duration = (float)(microtime(true)-$stamp);