diff --git a/lib/uuid.php b/lib/uuid.php
index 93153504f2..386d0e2121 100644
--- a/lib/uuid.php
+++ b/lib/uuid.php
@@ -47,6 +47,7 @@ if (!defined('STATUSNET')) {
 
 class UUID
 {
+    const REGEX = '[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}';
     protected $str = null;
 
     /**