diff --git a/libraries/SITL/SITL.cpp b/libraries/SITL/SITL.cpp
index 2154e3e700..cb07a4ac75 100644
--- a/libraries/SITL/SITL.cpp
+++ b/libraries/SITL/SITL.cpp
@@ -50,7 +50,6 @@ const AP_Param::GroupInfo SITL::var_info[] = {
     AP_GROUPINFO("GPS_TYPE",  12, SITL,  gps_type[0],  SITL::GPS_TYPE_UBLOX),
     AP_GROUPINFO("GPS_BYTELOSS",  13, SITL,  gps_byteloss,  0),
     AP_GROUPINFO("GPS_NUMSATS",   14, SITL,  gps_numsats,   10),
-    AP_GROUPINFO("MAG_ERROR",     15, SITL,  mag_error,  0),
     AP_GROUPINFO("SERVO_SPEED",   16, SITL,  servo_speed,  0.14),
     AP_GROUPINFO("GPS_GLITCH",    17, SITL,  gps_glitch[0],  0),
     AP_GROUPINFO("GPS_HZ",        18, SITL,  gps_hertz,  5),
@@ -117,7 +116,6 @@ const AP_Param::GroupInfo SITL::var_info2[] = {
     AP_GROUPINFO("ARSPD2_FAIL", 11, SITL,  arspd2_fail, 0),
     AP_GROUPINFO("ARSPD2_FAILP",12, SITL,  arspd2_fail_pressure, 0),
     AP_GROUPINFO("ARSPD2_PITOT",13, SITL,  arspd2_fail_pitot_pressure, 0),
-    AP_GROUPINFO("VICON_HSTLEN",14, SITL,  vicon_observation_history_length, 0),
     AP_GROUPINFO("WIND_T"      ,15, SITL,  wind_type, SITL::WIND_TYPE_SQRT),
     AP_GROUPINFO("WIND_T_ALT"  ,16, SITL,  wind_type_alt, 60),
     AP_GROUPINFO("WIND_T_COEF", 17, SITL,  wind_type_coef, 0.01f),
diff --git a/libraries/SITL/SITL.h b/libraries/SITL/SITL.h
index 4aaff8ff9d..06713c1eaf 100644
--- a/libraries/SITL/SITL.h
+++ b/libraries/SITL/SITL.h
@@ -148,10 +148,8 @@ public:
     AP_Float gps_noise; // amplitude of the gps altitude error
     AP_Int16 gps_lock_time; // delay in seconds before GPS gets lock
     AP_Int16 gps_alt_offset; // gps alt error
-    AP_Int8  vicon_observation_history_length; // frame delay for vicon messages
 
     AP_Float mag_noise;   // in mag units (earth field is 818)
-    AP_Float mag_error;   // in degrees
     AP_Vector3f mag_mot;  // in mag units per amp
     AP_Vector3f mag_ofs;  // in mag units
     AP_Vector3f mag_diag;  // diagonal corrections