diff --git a/message_definitions/v1.0/ardupilotmega.xml b/message_definitions/v1.0/ardupilotmega.xml
index 6501a7d0df..50f2852108 100644
--- a/message_definitions/v1.0/ardupilotmega.xml
+++ b/message_definitions/v1.0/ardupilotmega.xml
@@ -998,6 +998,9 @@
Set if EKF's predicted horizontal position (absolute) estimate is good.
+
+ Set if EKF believes the GPS input data is faulty.
+
Set if EKF has never been healthy.