diff --git a/composer.json b/composer.json
index 7707ac537cf..ee73b60f431 100644
--- a/composer.json
+++ b/composer.json
@@ -18,7 +18,7 @@
     },
     "scripts": {
         "cs:fix": "php-cs-fixer fix",
-        "cs:check": "php-cs-fixer fix --dry-run",
+        "cs:check": "php-cs-fixer fix --dry-run --diff",
         "lint": "find . -name \\*.php -not -path './lib/composer/*' -not -path './build/.phan/*' -exec php -l \"{}\" \\;"
     }
 }