diff --git a/HttpServer/Events/OnWorkerStart.php b/HttpServer/Events/OnWorkerStart.php
index 380a9c29..85cb5170 100644
--- a/HttpServer/Events/OnWorkerStart.php
+++ b/HttpServer/Events/OnWorkerStart.php
@@ -91,7 +91,7 @@ class OnWorkerStart extends Callback
 
 			$time = microtime(true);
 			$annotation->runtime(CONTROLLER_PATH);
-			$this->debug('use time.' . microtime(true) - $time);
+			$this->debug('use time.' . (microtime(true) - $time));
 			$annotation->runtime(directory('app'), CONTROLLER_PATH);
 
 			Snowflake::setWorkerId($server->worker_pid);