diff --git a/.phpcs.xml b/.phpcs.xml
index 3839d78..bea9751 100644
--- a/.phpcs.xml
+++ b/.phpcs.xml
@@ -1,6 +1,9 @@
 <?xml version="1.0"?>
 <ruleset>
-	<rule ref="./vendor/mediawiki/mediawiki-codesniffer/MediaWiki" />
+	<rule ref="./vendor/mediawiki/mediawiki-codesniffer/MediaWiki">
+		<exclude name="PSR12.Properties.ConstantVisibility.NotFound" />
+	</rule>
+
 	<file>.</file>
 	<arg name="extensions" value="php,php5,inc" />
 	<arg name="encoding" value="UTF-8" />
diff --git a/composer.json b/composer.json
index 846c716..7d562b0 100644
--- a/composer.json
+++ b/composer.json
@@ -6,7 +6,7 @@
 	"description": "MediaWiki extension to notify users if someone tries to login to their account",
 	"require-dev": {
 		"jakub-onderka/php-parallel-lint": "1.0.0",
-		"mediawiki/mediawiki-codesniffer": "26.0.0",
+		"mediawiki/mediawiki-codesniffer": "28.0.0",
 		"jakub-onderka/php-console-highlighter": "0.3.2",
 		"mediawiki/minus-x": "0.3.1",
 		"mediawiki/mediawiki-phan-config": "0.6.1"
diff --git a/tests/phpunit/LoginNotifyTest.php b/tests/phpunit/LoginNotifyTest.php
index d5a8f2c..135bd5d 100644
--- a/tests/phpunit/LoginNotifyTest.php
+++ b/tests/phpunit/LoginNotifyTest.php
@@ -1,7 +1,7 @@
 <?php
 
 use LoginNotify\LoginNotify;
-use \Psr\Log\NullLogger;
+use Psr\Log\NullLogger;
 use Wikimedia\TestingAccessWrapper;
 
 /**
@@ -36,7 +36,7 @@ class LoginNotifyTest extends MediaWikiTestCase {
 		$this->inst->setLogger( new NullLogger );
 	}
 
-	public function setUp() {
+	public function setUp() : void {
 		parent::setUp();
 		$this->setUpLoginNotify();
 	}