diff --git a/libraries/GCS_MAVLink/GCS_Common.cpp b/libraries/GCS_MAVLink/GCS_Common.cpp
index e28b47d46d..7342c32e71 100644
--- a/libraries/GCS_MAVLink/GCS_Common.cpp
+++ b/libraries/GCS_MAVLink/GCS_Common.cpp
@@ -3537,6 +3537,7 @@ MAV_RESULT GCS_MAVLINK::handle_command_preflight_calibration(const mavlink_comma
 {
     if (hal.util->get_soft_armed()) {
         // *preflight*, remember?
+        gcs().send_text(MAV_SEVERITY_NOTICE, "Disarm to allow calibration");
         return MAV_RESULT_FAILED;
     }
     // now call subclass methods: