diff --git a/src/Rbac.php b/src/Rbac.php
index bd632c5..643b3d7 100644
--- a/src/Rbac.php
+++ b/src/Rbac.php
@@ -52,7 +52,7 @@ public function addRole($role, $parents = null): void
             );
         }
 
-        if ($parents) {
+        if ($parents !== null) {
             $parents = is_array($parents) ? $parents : [$parents];
             /** @var RoleInterface|string $parent */
             foreach ($parents as $parent) {