diff --git a/src/modules/mavlink/mavlink_mission.cpp b/src/modules/mavlink/mavlink_mission.cpp
index 976f4e94a1..0327f94ec7 100644
--- a/src/modules/mavlink/mavlink_mission.cpp
+++ b/src/modules/mavlink/mavlink_mission.cpp
@@ -122,16 +122,21 @@ MavlinkMissionManager::init_offboard_mission()
 	mission_s mission_state;
 	if (!_dataman_init) {
 		_dataman_init = true;
-		if (dm_read(DM_KEY_MISSION_STATE, 0, &mission_state, sizeof(mission_s)) == sizeof(mission_s)) {
+		int ret = dm_read(DM_KEY_MISSION_STATE, 0, &mission_state, sizeof(mission_s)) == sizeof(mission_s);
+		if (ret > 0) {
 			_dataman_id = mission_state.dataman_id;
 			_count = mission_state.count;
 			_current_seq = mission_state.current_seq;
 
-		} else {
+		} else if (ret == 0) {
+			_dataman_id = 0;
+			_count = 0;
+			_current_seq = 0;
+		} else {
+			PX4_WARN("offboard mission init failed");
 			_dataman_id = 0;
 			_count = 0;
 			_current_seq = 0;
-			warnx("offboard mission init failed");
 		}
 	}
 	_my_dataman_id = _dataman_id;