diff --git a/composer.json b/composer.json
index f1ebaf9..986edd8 100644
--- a/composer.json
+++ b/composer.json
@@ -13,7 +13,8 @@
 		"silverstripe/framework": "^4"
 	},
     "require-dev": {
-        "phpunit/phpunit": "^5.7"
+        "phpunit/phpunit": "^5.7",
+        "squizlabs/php_codesniffer": "^3"
     },
 	"extra": {
         "branch-alias": {