diff --git a/composer.json b/composer.json
index 5a19733..74a1810 100644
--- a/composer.json
+++ b/composer.json
@@ -1,7 +1,7 @@
 {
 	"license": "GPL-2.0-or-later",
 	"require": {
-		"wikimedia/css-sanitizer": "^5.1.0 || ^5.2.0 || ^5.3.0"
+		"wikimedia/css-sanitizer": "^5.1.0 || ^5.2.0 || ^5.3.0 || ^5.4.0"
 	},
 	"require-dev": {
 		"mediawiki/mediawiki-codesniffer": "44.0.0",