diff --git a/libraries/AP_NavEKF3/AP_NavEKF3_MagFusion.cpp b/libraries/AP_NavEKF3/AP_NavEKF3_MagFusion.cpp
index 5d7c337be3..54936213e4 100644
--- a/libraries/AP_NavEKF3/AP_NavEKF3_MagFusion.cpp
+++ b/libraries/AP_NavEKF3/AP_NavEKF3_MagFusion.cpp
@@ -56,7 +56,7 @@ void NavEKF3_core::controlMagYawReset()
     if (flightResetAllowed && !assume_zero_sideslip()) {
         // check that we have reached a height where ground magnetic interference effects are insignificant
         // and can perform a final reset of the yaw and field states
-        finalResetRequest = (stateStruct.position.z  - posDownAtTakeoff) < -5.0f;
+        finalResetRequest = (stateStruct.position.z  - posDownAtTakeoff) < -EKF3_MAG_FINAL_RESET_ALT;
 
         // check for increasing height
         bool hgtIncreasing = (posDownAtLastMagReset-stateStruct.position.z) > 0.5f;
diff --git a/libraries/AP_NavEKF3/AP_NavEKF3_core.h b/libraries/AP_NavEKF3/AP_NavEKF3_core.h
index 045f190c72..8be7273a45 100644
--- a/libraries/AP_NavEKF3/AP_NavEKF3_core.h
+++ b/libraries/AP_NavEKF3/AP_NavEKF3_core.h
@@ -61,6 +61,9 @@
 #define EKF_TARGET_DT_MS 12
 #define EKF_TARGET_DT    0.012f
 
+// mag fusion final reset altitude (using NED frame so altitude is negative)
+#define EKF3_MAG_FINAL_RESET_ALT 2.5f
+
 class AP_AHRS;
 
 class NavEKF3_core