diff --git a/classes/phing/tasks/ext/zendguard/ZendGuardLicenseTask.php b/classes/phing/tasks/ext/zendguard/ZendGuardLicenseTask.php
index 21201999af..96af59b9cb 100644
--- a/classes/phing/tasks/ext/zendguard/ZendGuardLicenseTask.php
+++ b/classes/phing/tasks/ext/zendguard/ZendGuardLicenseTask.php
@@ -312,7 +312,7 @@ protected function verifyConfiguration()
 
             // check hardwareLocked
             if (null === $this->hardwareLocked) {
-                throw new BuildException("Property must be defined: " . $requiredProperty);
+                throw new BuildException("Property must be defined: hardwareLocked");
             }
 
             // if hardwareLocked is set to true, check that Host-ID is set