diff --git a/libraries/GCS_MAVLink/include/mavlink/v1.0/ardupilotmega/ardupilotmega.h b/libraries/GCS_MAVLink/include/mavlink/v1.0/ardupilotmega/ardupilotmega.h
index 92343b3ff2..eb07ea61aa 100644
--- a/libraries/GCS_MAVLink/include/mavlink/v1.0/ardupilotmega/ardupilotmega.h
+++ b/libraries/GCS_MAVLink/include/mavlink/v1.0/ardupilotmega/ardupilotmega.h
@@ -44,7 +44,7 @@ typedef enum MAV_CMD
 	MAV_CMD_NAV_LOITER_TURNS=18, /* Loiter around this MISSION for X turns |Turns| Empty| Radius around MISSION, in meters. If positive loiter clockwise, else counter-clockwise| Desired yaw angle.| Latitude| Longitude| Altitude|  */
 	MAV_CMD_NAV_LOITER_TIME=19, /* Loiter around this MISSION for X seconds |Seconds (decimal)| Empty| Radius around MISSION, in meters. If positive loiter clockwise, else counter-clockwise| Desired yaw angle.| Latitude| Longitude| Altitude|  */
 	MAV_CMD_NAV_RETURN_TO_LAUNCH=20, /* Return to launch location |Empty| Empty| Empty| Empty| Empty| Empty| Empty|  */
-	MAV_CMD_NAV_LAND=21, /* Land at location |Empty| Empty| Empty| Desired yaw angle.| Latitude| Longitude| Altitude|  */
+	MAV_CMD_NAV_LAND=21, /* Land at location |Abort Alt| Empty| Empty| Desired yaw angle.| Latitude| Longitude| Altitude|  */
 	MAV_CMD_NAV_TAKEOFF=22, /* Takeoff from ground / hand |Minimum pitch (if airspeed sensor present), desired pitch without sensor| Empty| Empty| Yaw angle (if magnetometer present), ignored without magnetometer| Latitude| Longitude| Altitude|  */
 	MAV_CMD_NAV_CONTINUE_AND_CHANGE_ALT=30, /* Continue on the current course and climb/descend to specified altitude.  When the altitude is reached continue to the next command (i.e., don't proceed to the next command until the desired altitude is reached. |Empty| Empty| Empty| Empty| Empty| Empty| Desired altitude in meters|  */
 	MAV_CMD_NAV_LOITER_TO_ALT=31, /* Begin loiter at the specified Latitude and Longitude.  If Lat=Lon=0, then loiter at the current position.  Don't consider the navigation command complete (don't leave loiter) until the altitude has been reached.  Additionally, if the Heading Required parameter is non-zero the  aircraft will not leave the loiter until heading toward the next waypoint.  |Heading Required (0 = False)| Radius in meters. If positive loiter clockwise, negative counter-clockwise, 0 means no change to standard loiter.| Empty| Empty| Latitude| Longitude| Altitude|  */