diff --git a/libraries/SITL/SITL.cpp b/libraries/SITL/SITL.cpp
index d6c52839e0..d0ae7236c0 100644
--- a/libraries/SITL/SITL.cpp
+++ b/libraries/SITL/SITL.cpp
@@ -44,6 +44,7 @@ const AP_Param::GroupInfo SITL::var_info[] PROGMEM = {
     AP_GROUPINFO("SERVO_RATE",    16, SITL,  servo_rate,  0),
     AP_GROUPINFO("GPS_GLITCH",    17, SITL,  gps_glitch,  0),
     AP_GROUPINFO("GPS_HZ",        18, SITL,  gps_hertz,  5),
+    AP_GROUPINFO("BATT_VOLTAGE",  19, SITL,  batt_voltage,  12.6),
     AP_GROUPEND
 };
 
diff --git a/libraries/SITL/SITL.h b/libraries/SITL/SITL.h
index db474966a8..04baa6335b 100644
--- a/libraries/SITL/SITL.h
+++ b/libraries/SITL/SITL.h
@@ -62,8 +62,9 @@ public:
     AP_Int8  gps_type;    // see enum GPSType
     AP_Float gps_byteloss;// byte loss as a percent
     AP_Int8  gps_numsats; // number of visible satellites
-    AP_Int8  gps_hertz;   // GPS update rate in Hz
     AP_Vector3f  gps_glitch;  // glitch offsets in lat, lon and altitude
+    AP_Int8  gps_hertz;   // GPS update rate in Hz
+    AP_Float batt_voltage; // battery voltage base
 
     // wind control
     AP_Float wind_speed;