diff --git a/msg/VehicleAttitude.msg b/msg/VehicleAttitude.msg
index 46e1fc0bcb..99e6f25c2e 100644
--- a/msg/VehicleAttitude.msg
+++ b/msg/VehicleAttitude.msg
@@ -1,4 +1,5 @@
 # This is similar to the mavlink message ATTITUDE_QUATERNION, but for onboard use
+# The quaternion uses the Hamilton convention, and the order is q(w, x, y, z)
 
 uint64 timestamp                # time since system start (microseconds)