diff --git a/Tests/Security/FirewallMapTest.php b/Tests/Security/FirewallMapTest.php
index fa590a54..7e49cd4f 100644
--- a/Tests/Security/FirewallMapTest.php
+++ b/Tests/Security/FirewallMapTest.php
@@ -23,7 +23,7 @@
 
 class FirewallMapTest extends TestCase
 {
-    const ATTRIBUTE_FIREWALL_CONTEXT = '_firewall_context';
+    private const ATTRIBUTE_FIREWALL_CONTEXT = '_firewall_context';
 
     public function testGetListenersWithEmptyMap()
     {