diff --git a/composer.json b/composer.json
index 6ad52c7..3e2c80b 100644
--- a/composer.json
+++ b/composer.json
@@ -5,7 +5,9 @@
     "homepage": "http://drupal.org/project/bootstrap_library",
     "license": "GPL-2.0+",
     "require": {
-        "twbs/bootstrap": "^4.4.1"
+        "twbs/bootstrap": "^4.4.1",
+        "php": "^7.1",
+        "drupal/core": "^8.7 || ^9"
     },
     "authors": [{
       "name": "Alberto Siles",