diff --git a/register_participants.inc.php b/register_participants.inc.php
index 1da08a53..5c0923c2 100644
--- a/register_participants.inc.php
+++ b/register_participants.inc.php
@@ -450,7 +450,7 @@ function addRegistration($userId){
 		return "register_participants.inc.php::addRegistration -> user not found";
 	}
 
-	if(!$row['registrations_id']){
+	if(intval($row['registrations_id'])){
 		return "register_participants.inc.php::addRegistration -> user already has a project registered";
 	}