diff --git a/test/backend.php b/test/backend.php
index b8836ee..deb408b 100644
--- a/test/backend.php
+++ b/test/backend.php
@@ -1,4 +1,4 @@
-<?php
+<?php // phpcs:ignore PSR1.Files.SideEffects
 
 header("Content-Type: application/json; charset=UTF-8");
 session_start();
@@ -8,7 +8,7 @@ define('LOG', 'log' . DS);
 // run id
 DEFINE('RUNUID', session_id());
 
-function logWrite($message)
+function logWrite(string $message): void
 {
 	global $fh;
 	if (!$fh) {
@@ -17,7 +17,7 @@ function logWrite($message)
 	fwrite($fh, '{' . RUNUID . '} [' . printTime() . '] ' . $message . "\n");
 }
 
-function logHandleClose()
+function logHandleClose(): void
 {
 	global $fh;
 	if ($fh) {
@@ -25,7 +25,7 @@ function logHandleClose()
 	}
 }
 
-function printTime()
+function printTime(): string
 {
 	$set_microtime = 4;
 	list($microtime, $timestamp) = explode(' ', microtime());