diff --git a/msg/vehicle_local_position.msg b/msg/vehicle_local_position.msg
index 409a56941e..f5a5d4c22a 100644
--- a/msg/vehicle_local_position.msg
+++ b/msg/vehicle_local_position.msg
@@ -45,7 +45,7 @@ bool z_global				# true if z has a valid global reference (ref_alt)
 uint64 ref_timestamp			# Time when reference position was set since system start, (microseconds)
 float64 ref_lat				# Reference point latitude, (degrees)
 float64 ref_lon				# Reference point longitude, (degrees)
-float32 ref_alt				# Reference altitude AMSL, MUST be set to current (not at reference point!) ground level, (metres)
+float32 ref_alt				# Reference altitude AMSL, (metres)
 
 # Distance to surface
 float32 dist_bottom			# Distance from from bottom surface to ground, (metres)