diff --git a/src/Symfony/Component/Security/Core/Role/RoleHierarchy.php b/src/Symfony/Component/Security/Core/Role/RoleHierarchy.php
index e625c0d6eb681..a0d2794dc3a0a 100644
--- a/src/Symfony/Component/Security/Core/Role/RoleHierarchy.php
+++ b/src/Symfony/Component/Security/Core/Role/RoleHierarchy.php
@@ -54,8 +54,11 @@ protected function buildRoleMap(): void
             $this->map[$main] = $roles;
             $visited = [];
             $additionalRoles = $roles;
-            while ($role = array_pop($additionalRoles)) {
+            while (null !== $role = key($additionalRoles)) {
+                $role = $additionalRoles[$role];
+
                 if (!isset($this->hierarchy[$role])) {
+                    next($additionalRoles);
                     continue;
                 }
 
@@ -68,6 +71,8 @@ protected function buildRoleMap(): void
                 foreach (array_diff($this->hierarchy[$role], $visited) as $additionalRole) {
                     $additionalRoles[] = $additionalRole;
                 }
+
+                next($additionalRoles);
             }
 
             $this->map[$main] = array_unique($this->map[$main]);