diff --git a/libraries/AP_HAL_AVR_SITL/sitl_gps.cpp b/libraries/AP_HAL_AVR_SITL/sitl_gps.cpp
index 85ed37f1d6..e2e3604c75 100644
--- a/libraries/AP_HAL_AVR_SITL/sitl_gps.cpp
+++ b/libraries/AP_HAL_AVR_SITL/sitl_gps.cpp
@@ -232,7 +232,7 @@ void SITL_State::_update_gps_ubx(const struct gps_data *d)
 	memset(&sol, 0, sizeof(sol));
 	sol.fix_type = d->have_lock?3:0;
 	sol.fix_status = 221;
-	sol.satellites = d->have_lock?10:3;
+	sol.satellites = d->have_lock?_sitl->gps_numsats:3;
 
 	_gps_send_ubx(MSG_POSLLH, (uint8_t*)&pos, sizeof(pos));
 	_gps_send_ubx(MSG_STATUS, (uint8_t*)&status, sizeof(status));
@@ -297,7 +297,7 @@ void SITL_State::_update_gps_mtk(const struct gps_data *d)
 	if (p.ground_course < 0.0) {
 		p.ground_course += 360.0 * 1000000.0;
 	}
-    p.satellites    = d->have_lock?10:3;
+    p.satellites    = d->have_lock?_sitl->gps_numsats:3;
     p.fix_type      = d->have_lock?3:1;
 
 	// the spec is not very clear, but the time field seems to be
@@ -353,7 +353,7 @@ void SITL_State::_update_gps_mtk16(const struct gps_data *d)
 	if (p.ground_course < 0.0) {
 		p.ground_course += 360.0 * 100.0;
 	}
-    p.satellites    = d->have_lock?10:3;
+    p.satellites    = d->have_lock?_sitl->gps_numsats:3;
     p.fix_type      = d->have_lock?3:1;
 
 	// the spec is not very clear, but the time field seems to be
@@ -411,7 +411,7 @@ void SITL_State::_update_gps_mtk19(const struct gps_data *d)
 	if (p.ground_course < 0.0) {
 		p.ground_course += 360.0 * 100.0;
 	}
-    p.satellites    = d->have_lock?10:3;
+    p.satellites    = d->have_lock?_sitl->gps_numsats:3;
     p.fix_type      = d->have_lock?3:1;
 
 	// the spec is not very clear, but the time field seems to be
diff --git a/libraries/SITL/SITL.cpp b/libraries/SITL/SITL.cpp
index 57a4966d8e..4a8ce29af9 100644
--- a/libraries/SITL/SITL.cpp
+++ b/libraries/SITL/SITL.cpp
@@ -28,6 +28,7 @@ const AP_Param::GroupInfo SITL::var_info[] PROGMEM = {
     AP_GROUPINFO("WIND_TURB", 11, SITL,  wind_turbulance,  0.2),
     AP_GROUPINFO("GPS_TYPE",  12, SITL,  gps_type,  SITL::GPS_TYPE_UBLOX),
     AP_GROUPINFO("GPS_BYTELOSS",  13, SITL,  gps_byteloss,  0),
+    AP_GROUPINFO("GPS_NUMSATS",   14, SITL,  gps_numsats,   10),
     AP_GROUPEND
 };
 
diff --git a/libraries/SITL/SITL.h b/libraries/SITL/SITL.h
index 9f02a87fb3..71a6f6fafa 100644
--- a/libraries/SITL/SITL.h
+++ b/libraries/SITL/SITL.h
@@ -60,6 +60,7 @@ public:
 	AP_Int8  gps_delay;   // delay in samples
     AP_Int8  gps_type;    // see enum GPSType
     AP_Float gps_byteloss;// byte loss as a percent
+    AP_Int8  gps_numsats; // number of visible satellites
 
     // wind control
     AP_Float wind_speed;