diff --git a/msg/VehicleThrustSetpoint.msg b/msg/VehicleThrustSetpoint.msg
index 444ee50032b..36693d55540 100644
--- a/msg/VehicleThrustSetpoint.msg
+++ b/msg/VehicleThrustSetpoint.msg
@@ -1,8 +1,11 @@
+# Vehicle thrust setpoint
+#
+# This is the thrust setpoint provided by the controller and fed into the control allocator.
 
-uint64 timestamp        # time since system start (microseconds)
-uint64 timestamp_sample # timestamp of the data sample on which this message is based (microseconds)
+uint64 timestamp        # [us] Time since system start
+uint64 timestamp_sample # [us] Timestamp of the data sample on which this message is based
 
-float32[3] xyz          # thrust setpoint along X, Y, Z body axis [-1, 1]
+float32[3] xyz          # [-] [@range -1, 1] Thrust setpoint along X, Y, Z body axis. If set to NAN the motors affecting this axis are stopped.
 
 # TOPICS vehicle_thrust_setpoint
 # TOPICS vehicle_thrust_setpoint_virtual_fw vehicle_thrust_setpoint_virtual_mc
diff --git a/src/modules/land_detector/MulticopterLandDetector.cpp b/src/modules/land_detector/MulticopterLandDetector.cpp
index dfccc351632..05497134236 100644
--- a/src/modules/land_detector/MulticopterLandDetector.cpp
+++ b/src/modules/land_detector/MulticopterLandDetector.cpp
@@ -89,7 +89,7 @@ void MulticopterLandDetector::_update_topics()
 	vehicle_thrust_setpoint_s vehicle_thrust_setpoint;
 
 	if (_vehicle_thrust_setpoint_sub.update(&vehicle_thrust_setpoint)) {
-		_vehicle_thrust_setpoint_throttle = -vehicle_thrust_setpoint.xyz[2];
+		_vehicle_thrust_setpoint_throttle = PX4_ISFINITE(vehicle_thrust_setpoint.xyz[2]) ? -vehicle_thrust_setpoint.xyz[2] : 0.f;
 		_vehicle_thrust_setpoint_last_update = hrt_absolute_time();
 	}