diff --git a/guides/security/acl.rst b/guides/security/acl.rst
index fc929f829bf..f6655f1cdf3 100644
--- a/guides/security/acl.rst
+++ b/guides/security/acl.rst
@@ -58,6 +58,14 @@ First, we need to configure the connection the ACL system is supposed to use:
         ));
 
 
+.. note::
+
+    The ACL system requires at least one Doctrine DBAL connection to be
+    configured. However, that does not mean that you have to use Doctrine for
+    mapping your domain objects. You can use whatever mapper you like for your
+    objects, be it Doctrine ORM, Mongo ODM, Propel, or raw SQL, the choice is 
+    yours.
+
 After the connection is configured. We have to import the database structure.
 Fortunately, we have a task for this. Simply run the following command: