diff --git a/actions/register.php b/actions/register.php
index a6c1a903aa..57f8e7bdf0 100644
--- a/actions/register.php
+++ b/actions/register.php
@@ -55,6 +55,12 @@ class RegisterAction extends Action
 
     var $registered = false;
 
+    /**
+     * Are we processing an invite?
+     */
+
+    var $invite = null;
+
     /**
      * Prepare page to run
      *