diff --git a/composer.json b/composer.json
index 554843a..9454e89 100644
--- a/composer.json
+++ b/composer.json
@@ -4,7 +4,7 @@
 		"wikimedia/css-sanitizer": "~4.0.0"
 	},
 	"require-dev": {
-		"mediawiki/mediawiki-codesniffer": "39.0.0",
+		"mediawiki/mediawiki-codesniffer": "40.0.1",
 		"mediawiki/mediawiki-phan-config": "0.12.0",
 		"mediawiki/minus-x": "1.1.1",
 		"php-parallel-lint/php-console-highlighter": "1.0.0",