diff --git a/composer.json b/composer.json
index c301826..198ff16 100644
--- a/composer.json
+++ b/composer.json
@@ -11,6 +11,7 @@
     }
   ],
   "require": {
+    "craftcms/cms": "^3.0.0",
     "php": ">=7.0",
     "rlanvin/php-rrule": "~1.6.0",
     "symfony/property-access": "^2.8|^3.0|^4.0",