diff --git a/composer.json b/composer.json
index ccad6a7..228ab8c 100644
--- a/composer.json
+++ b/composer.json
@@ -26,6 +26,7 @@
         "phpunit/phpunit": "^10",
         "phpstan/phpstan": "^1",
         "sweetrdf/simple-rdf": "^2.0.0-RC7",
+        "sweetrdf/rdf-helpers": "^2.0.0-RC1",
         "php-coveralls/php-coveralls": "^2.4"
     },
     "autoload-dev": {