diff --git a/fkie_master_discovery/src/fkie_master_discovery/master_discovery.py b/fkie_master_discovery/src/fkie_master_discovery/master_discovery.py
index 1403687f..c3fafcd1 100644
--- a/fkie_master_discovery/src/fkie_master_discovery/master_discovery.py
+++ b/fkie_master_discovery/src/fkie_master_discovery/master_discovery.py
@@ -1056,6 +1056,7 @@ def _crossbar_publish_masters(self):
                                                master.masteruri) > 0 else f'{addr}:{port}',
                                            origin=master.masteruri == self.master_monitor.getMasteruri(),
                                            hostnames=list(set([addr[0], get_hostname(master.masteruri)])))
+                    cbmaster.ros_domain_id = self.mcast_port - 11511
                     result.append(cbmaster)
                     crossbar_reported_masters.add(master.masteruri)
             if not (crossbar_reported_masters == self._crossbar_reported_masters):