diff --git a/composer.json b/composer.json
index f664db8..2776f8b 100644
--- a/composer.json
+++ b/composer.json
@@ -18,7 +18,7 @@
         "silverstripe/framework": "^4"
     },
     "require-dev": {
-        "phpunit/PHPUnit": "^5.7",
+        "phpunit/phpunit": "^5.7",
         "squizlabs/php_codesniffer": "^3.0",
         "silverstripe/versioned": "^1"
     },