diff --git a/composer.json b/composer.json
index 4bb6352..091b9a4 100644
--- a/composer.json
+++ b/composer.json
@@ -17,7 +17,8 @@
         "tedivm/stash": "^0.14.1",
         "doctrine/collections": "^1.4",
         "ircmaxell/security-lib": "^1.1",
-        "ircmaxell/random-lib": "^1.2"
+        "ircmaxell/random-lib": "^1.2",
+        "sikofitt/retrorsum": "^1.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^6.0",