diff --git a/ArduPlane/GCS_Mavlink.cpp b/ArduPlane/GCS_Mavlink.cpp
index f1002ccbbd..28fedcac0c 100644
--- a/ArduPlane/GCS_Mavlink.cpp
+++ b/ArduPlane/GCS_Mavlink.cpp
@@ -266,6 +266,7 @@ void Plane::send_extended_status1(mavlink_channel_t chan)
     }
 #endif
 
+#if RANGEFINDER_ENABLED == ENABLED
     if (rangefinder.num_sensors() > 0) {
         control_sensors_present |= MAV_SYS_STATUS_SENSOR_LASER_POSITION;
         if (g.rangefinder_landing) {
@@ -275,6 +276,7 @@ void Plane::send_extended_status1(mavlink_channel_t chan)
             control_sensors_health |= MAV_SYS_STATUS_SENSOR_LASER_POSITION;            
         }
     }
+#endif
 
     if (AP_Notify::flags.initialising) {
         // while initialising the gyros and accels are not enabled
@@ -456,6 +458,7 @@ void Plane::send_wind(mavlink_channel_t chan)
 
 void Plane::send_rangefinder(mavlink_channel_t chan)
 {
+#if RANGEFINDER_ENABLED == ENABLED
     if (!rangefinder.has_data()) {
         // no sonar to report
         return;
@@ -464,6 +467,7 @@ void Plane::send_rangefinder(mavlink_channel_t chan)
         chan,
         rangefinder.distance_cm() * 0.01f,
         rangefinder.voltage_mv()*0.001f);
+#endif
 }
 
 void Plane::send_current_waypoint(mavlink_channel_t chan)
diff --git a/ArduPlane/Log.cpp b/ArduPlane/Log.cpp
index 212b3d8b45..a51d299724 100644
--- a/ArduPlane/Log.cpp
+++ b/ArduPlane/Log.cpp
@@ -357,6 +357,7 @@ struct PACKED log_Sonar {
 // Write a sonar packet
 void Plane::Log_Write_Sonar()
 {
+#if RANGEFINDER_ENABLED == ENABLED
     struct log_Sonar pkt = {
         LOG_PACKET_HEADER_INIT(LOG_SONAR_MSG),
         timestamp   : millis(),
@@ -369,6 +370,7 @@ void Plane::Log_Write_Sonar()
         correction  : rangefinder_state.correction
     };
     DataFlash.WriteBlock(&pkt, sizeof(pkt));
+#endif
 }
 
 struct PACKED log_Optflow {
diff --git a/ArduPlane/Parameters.cpp b/ArduPlane/Parameters.cpp
index af05440961..88e1f657d0 100644
--- a/ArduPlane/Parameters.cpp
+++ b/ArduPlane/Parameters.cpp
@@ -987,9 +987,11 @@ const AP_Param::Info Plane::var_info[] PROGMEM = {
     // @Path: ../libraries/AP_Relay/AP_Relay.cpp
     GOBJECT(relay,                  "RELAY_", AP_Relay),
 
+#if RANGEFINDER_ENABLED == ENABLED
     // @Group: RNGFND
     // @Path: ../libraries/AP_RangeFinder/RangeFinder.cpp
     GOBJECT(rangefinder,            "RNGFND", RangeFinder),
+#endif
 
     // @Param: RNGFND_LANDING
     // @DisplayName: Enable rangefinder for landing
diff --git a/ArduPlane/Plane.h b/ArduPlane/Plane.h
index 33ceb50523..65131d2c66 100644
--- a/ArduPlane/Plane.h
+++ b/ArduPlane/Plane.h
@@ -233,6 +233,7 @@ private:
     // a pin for reading the receiver RSSI voltage. 
     AP_HAL::AnalogSource *rssi_analog_source;
 
+#if RANGEFINDER_ENABLED == ENABLED
     // rangefinder
     RangeFinder rangefinder;
 
@@ -242,6 +243,7 @@ private:
         uint32_t last_correction_time_ms;
         uint8_t in_range_count;
     } rangefinder_state;
+#endif
 
     // Relay
     AP_Relay relay;
diff --git a/ArduPlane/altitude.cpp b/ArduPlane/altitude.cpp
index d08ed5a5a7..66ab26a1a3 100644
--- a/ArduPlane/altitude.cpp
+++ b/ArduPlane/altitude.cpp
@@ -525,6 +525,7 @@ float Plane::lookahead_adjustment(void)
  */
 float Plane::rangefinder_correction(void)
 {
+#if RANGEFINDER_ENABLED == ENABLED
     if (millis() - rangefinder_state.last_correction_time_ms > 5000) {
         // we haven't had any rangefinder data for 5s - don't use it
         return 0;
@@ -540,9 +541,12 @@ float Plane::rangefinder_correction(void)
     }
 
     return rangefinder_state.correction;
+#else
+    return 0;
+#endif
 }
 
-
+#if RANGEFINDER_ENABLED == ENABLED
 /*
   update the offset between rangefinder height and terrain height
  */
@@ -591,3 +595,4 @@ void Plane::rangefinder_height_update(void)
         rangefinder_state.last_correction_time_ms = millis();    
     }
 }
+#endif
diff --git a/ArduPlane/config.h b/ArduPlane/config.h
index 265dc37188..1b321e8435 100644
--- a/ArduPlane/config.h
+++ b/ArduPlane/config.h
@@ -63,10 +63,10 @@
 //
 
 #ifndef FRSKY_TELEM_ENABLED
-#if CONFIG_HAL_BOARD == HAL_BOARD_APM1 || CONFIG_HAL_BOARD == HAL_BOARD_APM2
- # define FRSKY_TELEM_ENABLED DISABLED
-#else
+#if HAL_CPU_CLASS > HAL_CPU_CLASS_16
  # define FRSKY_TELEM_ENABLED ENABLED
+#else
+ # define FRSKY_TELEM_ENABLED DISABLED
 #endif
 #endif
 
@@ -82,6 +82,12 @@
 #endif
 #endif
 
+#if HAL_CPU_CLASS > HAL_CPU_CLASS_16
+# define RANGEFINDER_ENABLED ENABLED
+#else
+# define RANGEFINDER_ENABLED DISABLED
+#endif
+
 //////////////////////////////////////////////////////////////////////////////
 //////////////////////////////////////////////////////////////////////////////
 // RADIO CONFIGURATION
diff --git a/ArduPlane/landing.cpp b/ArduPlane/landing.cpp
index aa7c4b7c48..c2992e9c06 100644
--- a/ArduPlane/landing.cpp
+++ b/ArduPlane/landing.cpp
@@ -52,9 +52,14 @@ bool Plane::verify_land()
           rangefinder data (to prevent us keeping throttle on 
           after landing if we've had positive baro drift)
     */
+#if RANGEFINDER_ENABLED == ENABLED
+    bool rangefinder_in_range = rangefinder_state.in_range;
+#else
+    bool rangefinder_in_range = false;
+#endif
     if (height <= g.land_flare_alt ||
         (aparm.land_flare_sec > 0 && height <= auto_state.land_sink_rate * aparm.land_flare_sec) ||
-        (!rangefinder_state.in_range && location_passed_point(current_loc, prev_WP_loc, next_WP_loc)) ||
+        (!rangefinder_in_range && location_passed_point(current_loc, prev_WP_loc, next_WP_loc)) ||
         (fabsf(auto_state.land_sink_rate) < 0.2f && !is_flying())) {
 
         if (!auto_state.land_complete) {
diff --git a/ArduPlane/sensors.cpp b/ArduPlane/sensors.cpp
index 2c3f2631dc..0252c89856 100644
--- a/ArduPlane/sensors.cpp
+++ b/ArduPlane/sensors.cpp
@@ -12,7 +12,9 @@ void Plane::init_barometer(void)
 
 void Plane::init_rangefinder(void)
 {
+#if RANGEFINDER_ENABLED == ENABLED
     rangefinder.init();
+#endif
 }
 
 /*
@@ -20,12 +22,14 @@ void Plane::init_rangefinder(void)
  */
 void Plane::read_rangefinder(void)
 {
+#if RANGEFINDER_ENABLED == ENABLED
     rangefinder.update();
 
     if (should_log(MASK_LOG_SONAR))
         Log_Write_Sonar();
 
     rangefinder_height_update();
+#endif
 }
 
 /*