diff --git a/ArduSub/GCS_Mavlink.cpp b/ArduSub/GCS_Mavlink.cpp
index 4de5f9894d..7c211337ef 100644
--- a/ArduSub/GCS_Mavlink.cpp
+++ b/ArduSub/GCS_Mavlink.cpp
@@ -226,7 +226,7 @@ bool GCS_MAVLINK_Sub::try_send_message(enum ap_message id)
         break;
 
     case MSG_TERRAIN:
-#if AP_TERRAIN_AVAILABLE && AC_TERRAIN
+#if AP_TERRAIN_AVAILABLE
         CHECK_PAYLOAD_SIZE(TERRAIN_REQUEST);
         sub.terrain.send_request(chan);
 #endif
@@ -361,7 +361,7 @@ static const ap_message STREAM_EXTRA3_msgs[] = {
     MSG_SYSTEM_TIME,
     MSG_RANGEFINDER,
     MSG_DISTANCE_SENSOR,
-#if AP_TERRAIN_AVAILABLE && AC_TERRAIN
+#if AP_TERRAIN_AVAILABLE
     MSG_TERRAIN,
 #endif
     MSG_BATTERY2,
@@ -709,7 +709,7 @@ void GCS_MAVLINK_Sub::handleMessage(const mavlink_message_t &msg)
 
     case MAVLINK_MSG_ID_TERRAIN_DATA:
     case MAVLINK_MSG_ID_TERRAIN_CHECK:
-#if AP_TERRAIN_AVAILABLE && AC_TERRAIN
+#if AP_TERRAIN_AVAILABLE
         sub.terrain.handle_data(chan, msg);
 #endif
         break;
@@ -761,7 +761,7 @@ uint64_t GCS_MAVLINK_Sub::capabilities() const
             MAV_PROTOCOL_CAPABILITY_SET_POSITION_TARGET_LOCAL_NED |
             MAV_PROTOCOL_CAPABILITY_SET_POSITION_TARGET_GLOBAL_INT |
             MAV_PROTOCOL_CAPABILITY_FLIGHT_TERMINATION |
-#if AP_TERRAIN_AVAILABLE && AC_TERRAIN
+#if AP_TERRAIN_AVAILABLE
             (sub.terrain.enabled() ? MAV_PROTOCOL_CAPABILITY_TERRAIN : 0) |
 #endif
             MAV_PROTOCOL_CAPABILITY_SET_ATTITUDE_TARGET |
diff --git a/ArduSub/GCS_Sub.cpp b/ArduSub/GCS_Sub.cpp
index 3ce89cd420..5f0aea7c05 100644
--- a/ArduSub/GCS_Sub.cpp
+++ b/ArduSub/GCS_Sub.cpp
@@ -67,7 +67,7 @@ void GCS_Sub::update_vehicle_sensor_status_flags()
     }
 #endif
 
-#if AP_TERRAIN_AVAILABLE && AC_TERRAIN
+#if AP_TERRAIN_AVAILABLE
     switch (sub.terrain.status()) {
     case AP_Terrain::TerrainStatusDisabled:
         break;
diff --git a/ArduSub/Log.cpp b/ArduSub/Log.cpp
index f2c8dabb65..085fe6ecba 100644
--- a/ArduSub/Log.cpp
+++ b/ArduSub/Log.cpp
@@ -27,7 +27,7 @@ void Sub::Log_Write_Control_Tuning()
 {
     // get terrain altitude
     float terr_alt = 0.0f;
-#if AP_TERRAIN_AVAILABLE && AC_TERRAIN
+#if AP_TERRAIN_AVAILABLE
     terrain.height_above_terrain(terr_alt, true);
 #endif
 
diff --git a/ArduSub/Parameters.cpp b/ArduSub/Parameters.cpp
index c57040f37d..2f7731310e 100644
--- a/ArduSub/Parameters.cpp
+++ b/ArduSub/Parameters.cpp
@@ -593,7 +593,7 @@ const AP_Param::Info Sub::var_info[] = {
     GOBJECT(rangefinder,   "RNGFND", RangeFinder),
 #endif
 
-#if AP_TERRAIN_AVAILABLE && AC_TERRAIN
+#if AP_TERRAIN_AVAILABLE
     // @Group: TERRAIN_
     // @Path: ../libraries/AP_Terrain/AP_Terrain.cpp
     GOBJECT(terrain,                "TERRAIN_", AP_Terrain),
diff --git a/ArduSub/Sub.h b/ArduSub/Sub.h
index 327e8decb1..502c8b4373 100644
--- a/ArduSub/Sub.h
+++ b/ArduSub/Sub.h
@@ -372,7 +372,7 @@ private:
 #endif
 
     // terrain handling
-#if AP_TERRAIN_AVAILABLE && AC_TERRAIN
+#if AP_TERRAIN_AVAILABLE
     AP_Terrain terrain{mission};
 #endif
 
diff --git a/ArduSub/config.h b/ArduSub/config.h
index 63a7bc6c97..02e92978f1 100644
--- a/ArduSub/config.h
+++ b/ArduSub/config.h
@@ -244,7 +244,3 @@
 #ifndef AC_RALLY
 #define AC_RALLY   DISABLED
 #endif
-
-#ifndef AC_TERRAIN
-#define AC_TERRAIN DISABLED // Requires Rally enabled as well
-#endif
diff --git a/ArduSub/system.cpp b/ArduSub/system.cpp
index fad675a587..048db99cc6 100644
--- a/ArduSub/system.cpp
+++ b/ArduSub/system.cpp
@@ -84,7 +84,7 @@ void Sub::init_ardupilot()
     AP::compass().init();
 
     // init Location class
-#if AP_TERRAIN_AVAILABLE && AC_TERRAIN
+#if AP_TERRAIN_AVAILABLE
     Location::set_terrain(&terrain);
     wp_nav.set_terrain(&terrain);
 #endif
diff --git a/ArduSub/terrain.cpp b/ArduSub/terrain.cpp
index 32ca8616c8..30b7351ce4 100644
--- a/ArduSub/terrain.cpp
+++ b/ArduSub/terrain.cpp
@@ -3,7 +3,7 @@
 // update terrain data
 void Sub::terrain_update()
 {
-#if AP_TERRAIN_AVAILABLE && AC_TERRAIN
+#if AP_TERRAIN_AVAILABLE
     terrain.update();
 
     // tell the rangefinder our height, so it can go into power saving
@@ -20,7 +20,7 @@ void Sub::terrain_update()
 // log terrain data - should be called at 1hz
 void Sub::terrain_logging()
 {
-#if AP_TERRAIN_AVAILABLE && AC_TERRAIN
+#if AP_TERRAIN_AVAILABLE
     if (should_log(MASK_LOG_GPS)) {
         terrain.log_terrain_data();
     }