diff --git a/fsm.h b/fsm.h
index 90c7a4d..5d4ae91 100644
--- a/fsm.h
+++ b/fsm.h
@@ -28,10 +28,10 @@ enum port_state {
 	PS_LISTENING,
 	PS_PRE_MASTER,
 	PS_MASTER,
-	PS_GRAND_MASTER,
 	PS_PASSIVE,
 	PS_UNCALIBRATED,
 	PS_SLAVE,
+	PS_GRAND_MASTER, /*non-standard extension*/
 };
 
 /** Defines the events for the port state machine. */
diff --git a/phc2sys.c b/phc2sys.c
index 17d00db..8e6b79f 100644
--- a/phc2sys.c
+++ b/phc2sys.c
@@ -383,7 +383,6 @@ static int run_pmc(int wait_sync, int *utc_offset)
 
 			switch (((struct portDS *)data)->portState) {
 			case PS_MASTER:
-			case PS_GRAND_MASTER:
 			case PS_SLAVE:
 				ds_done = 1;
 				break;
diff --git a/port.c b/port.c
index 6c9bd32..0112cb3 100644
--- a/port.c
+++ b/port.c
@@ -457,7 +457,11 @@ static int port_management_get_response(struct port *target,
 	case PORT_DATA_SET:
 		pds = (struct portDS *) tlv->data;
 		pds->portIdentity            = target->portIdentity;
-		pds->portState               = target->state;
+		if (target->state == PS_GRAND_MASTER) {
+			pds->portState = PS_MASTER;
+		} else {
+			pds->portState = target->state;
+		}
 		pds->logMinDelayReqInterval  = target->logMinDelayReqInterval;
 		pds->peerMeanPathDelay       = target->peerMeanPathDelay;
 		pds->logAnnounceInterval     = target->logAnnounceInterval;