diff --git a/libraries/AP_Baro/AP_Baro.cpp b/libraries/AP_Baro/AP_Baro.cpp
index 4cf2f4e725..2d7371ae43 100644
--- a/libraries/AP_Baro/AP_Baro.cpp
+++ b/libraries/AP_Baro/AP_Baro.cpp
@@ -1112,7 +1112,8 @@ bool AP_Baro::arming_checks(size_t buflen, char *buffer) const
     const auto &gps = AP::gps();
     if (_alt_error_max > 0 && gps.status() >= AP_GPS::GPS_Status::GPS_OK_FIX_3D) {
         const float alt_amsl = gps.location().alt*0.01;
-        const float alt_pressure = get_altitude_difference(SSL_AIR_PRESSURE, get_pressure());
+        // note the addition of _field_elevation_active as this is subtracted in get_altitude_difference()
+        const float alt_pressure = get_altitude_difference(SSL_AIR_PRESSURE, get_pressure()) + _field_elevation_active;
         const float error = fabsf(alt_amsl - alt_pressure);
         if (error > _alt_error_max) {
             hal.util->snprintf(buffer, buflen, "GPS alt error %.0fm (see BARO_ALTERR_MAX)", error);