diff --git a/Tools/scripts/build_options.py b/Tools/scripts/build_options.py
index a5a112a220..09d65181dd 100644
--- a/Tools/scripts/build_options.py
+++ b/Tools/scripts/build_options.py
@@ -344,6 +344,7 @@ BUILD_OPTIONS = [
     Feature('MAVLink', 'MAV_MSG_SERIAL_CONTROL', 'AP_MAVLINK_MSG_SERIAL_CONTROL_ENABLED', 'Enable handling of Serial Control mavlink messages', 0, None),  # noqa
     Feature('MAVLink', 'MAVLINK_MSG_MISSION_REQUEST', 'AP_MAVLINK_MSG_MISSION_REQUEST_ENABLED', 'Enable handling of MISSION_REQUEST mavlink messages', 0, None),  # noqa
     Feature('MAVLink', 'AP_MAVLINK_FTP_ENABLED', 'AP_MAVLINK_FTP_ENABLED', 'Enable MAVLink FTP Protocol', 0, None),  # noqa
+    Feature('MAVLink', 'MAV_CMD_SEY_HAGL', 'AP_MAVLINK_MAV_CMD_SEY_HAGL_ENABLED', 'Enable MAVLink HAGL command', 0, None),  # noqa
 
     Feature('Developer', 'KILL_IMU', 'AP_INERTIALSENSOR_KILL_IMU_ENABLED', 'Allow IMUs to be disabled at runtime', 0, None),
     Feature('Developer', 'CRASHCATCHER', 'AP_CRASHDUMP_ENABLED', 'Enable CrashCatcher', 0, None),
diff --git a/Tools/scripts/extract_features.py b/Tools/scripts/extract_features.py
index 63a83863f0..6b3238f1f4 100755
--- a/Tools/scripts/extract_features.py
+++ b/Tools/scripts/extract_features.py
@@ -238,6 +238,7 @@ class ExtractFeatures(object):
             ('AP_MAVLINK_MSG_SERIAL_CONTROL_ENABLED', 'GCS_MAVLINK::handle_serial_control'),
             ('AP_MAVLINK_MSG_MISSION_REQUEST_ENABLED', 'GCS_MAVLINK::handle_mission_request\b'),
             ('AP_MAVLINK_FTP_ENABLED', 'GCS_MAVLINK::ftp_worker'),
+            ('AP_MAVLINK_MAV_CMD_SEY_HAGL_ENABLED', 'Plane::get_external_HAGL'),
 
             ('AP_DRONECAN_HIMARK_SERVO_SUPPORT', 'AP_DroneCAN::SRV_send_himark'),
             ('AP_DRONECAN_HOBBYWING_ESC_SUPPORT', 'AP_DroneCAN::hobbywing_ESC_update'),