diff --git a/ArduCopter/control_land.pde b/ArduCopter/control_land.pde
index ede866862b..9b4adc5bac 100644
--- a/ArduCopter/control_land.pde
+++ b/ArduCopter/control_land.pde
@@ -174,8 +174,13 @@ static void land_nogps_run()
 //      should be called at 100hz or higher
 static float get_throttle_land()
 {
+#if CONFIG_SONAR == ENABLED
+    bool sonar_ok = sonar_enabled && sonar.healthy();
+#else
+    bool sonar_ok = false;
+#endif
     // if we are above 10m and the sonar does not sense anything perform regular alt hold descent
-    if (current_loc.alt >= LAND_START_ALT && !(sonar_enabled && sonar.healthy() && sonar_alt_health >= SONAR_ALT_HEALTH_MAX)) {
+    if (current_loc.alt >= LAND_START_ALT && !(sonar_ok && sonar_alt_health >= SONAR_ALT_HEALTH_MAX)) {
         return pos_control.get_speed_down();
     }else{
         return -abs(g.land_speed);
diff --git a/ArduCopter/control_modes.pde b/ArduCopter/control_modes.pde
index ac26da5749..6f92fe868a 100644
--- a/ArduCopter/control_modes.pde
+++ b/ArduCopter/control_modes.pde
@@ -258,11 +258,13 @@ static void do_aux_switch_function(int8_t ch_function, uint8_t ch_flag)
 
         case AUX_SWITCH_SONAR:
             // enable or disable the sonar
+#if CONFIG_SONAR == ENABLED
             if (ch_flag == AUX_SWITCH_HIGH) {
                 sonar_enabled = true;
             }else{
                 sonar_enabled = false;
             }
+#endif
             break;
 
 #if AC_FENCE == ENABLED