diff --git a/msg/sensor_preflight.msg b/msg/sensor_preflight.msg
index 81d8e028f1..293953f886 100644
--- a/msg/sensor_preflight.msg
+++ b/msg/sensor_preflight.msg
@@ -4,3 +4,4 @@
 #
 float32 accel_inconsistency_m_s_s  # magnitude of maximum acceleration difference between IMU instances in (m/s/s).
 float32 gyro_inconsistency_rad_s   # magnitude of maximum angular rate difference between IMU instances in (rad/s).
+float32 mag_inconsistency_ga       # magnitude of maximum difference between Mag instances in (Gauss).