diff --git a/libraries/GCS_MAVLink/GCS_Common.cpp b/libraries/GCS_MAVLink/GCS_Common.cpp
index 7b2749aeec..de79b6d764 100644
--- a/libraries/GCS_MAVLink/GCS_Common.cpp
+++ b/libraries/GCS_MAVLink/GCS_Common.cpp
@@ -3874,12 +3874,15 @@ void GCS_MAVLINK::handle_common_message(const mavlink_message_t &msg)
         handle_set_gps_global_origin(msg);
         break;
 
+#if AP_MAVLINK_MSG_DEVICE_OP_ENABLED
     case MAVLINK_MSG_ID_DEVICE_OP_READ:
         handle_device_op_read(msg);
         break;
     case MAVLINK_MSG_ID_DEVICE_OP_WRITE:
         handle_device_op_write(msg);
         break;
+#endif
+
     case MAVLINK_MSG_ID_TIMESYNC:
         handle_timesync(msg);
         break;
@@ -3973,9 +3976,11 @@ void GCS_MAVLINK::handle_common_message(const mavlink_message_t &msg)
         handle_param_value(msg);
         break;
 
+#if AP_MAVLINK_MSG_SERIAL_CONTROL_ENABLED
     case MAVLINK_MSG_ID_SERIAL_CONTROL:
         handle_serial_control(msg);
         break;
+#endif
 
     case MAVLINK_MSG_ID_GPS_RTCM_DATA:
     case MAVLINK_MSG_ID_GPS_INPUT:
@@ -5139,7 +5144,7 @@ MAV_RESULT GCS_MAVLINK::handle_command_int_packet(const mavlink_command_int_t &p
         return handle_command_mag_cal(packet);
 #endif
 
-#if AP_SERVORELAYEVENTS_ENABLED
+#if AP_MAVLINK_SERVO_RELAY_ENABLED
     case MAV_CMD_DO_SET_SERVO:
     case MAV_CMD_DO_REPEAT_SERVO:
     case MAV_CMD_DO_SET_RELAY:
diff --git a/libraries/GCS_MAVLink/GCS_DeviceOp.cpp b/libraries/GCS_MAVLink/GCS_DeviceOp.cpp
index b7418ad78c..ddaa450c71 100644
--- a/libraries/GCS_MAVLink/GCS_DeviceOp.cpp
+++ b/libraries/GCS_MAVLink/GCS_DeviceOp.cpp
@@ -15,6 +15,11 @@
 /*
   handle device operations over MAVLink
  */
+
+#include "GCS_config.h"
+
+#if AP_MAVLINK_MSG_DEVICE_OP_ENABLED
+
 #include <AP_HAL/AP_HAL.h>
 #include <AP_HAL/Device.h>
 #include <AP_HAL/I2CDevice.h>
@@ -137,3 +142,5 @@ fail:
         packet.request_id,
         retcode);
 }
+
+#endif  // AP_MAVLINK_MSG_DEVICE_OP_ENABLED
diff --git a/libraries/GCS_MAVLink/GCS_ServoRelay.cpp b/libraries/GCS_MAVLink/GCS_ServoRelay.cpp
index 105d27f50f..c624268763 100644
--- a/libraries/GCS_MAVLink/GCS_ServoRelay.cpp
+++ b/libraries/GCS_MAVLink/GCS_ServoRelay.cpp
@@ -2,7 +2,7 @@
 
 #include "AP_ServoRelayEvents/AP_ServoRelayEvents.h"
 
-#if AP_SERVORELAYEVENTS_ENABLED
+#if AP_MAVLINK_SERVO_RELAY_ENABLED
 
 MAV_RESULT GCS_MAVLINK::handle_servorelay_message(const mavlink_command_int_t &packet)
 {
@@ -48,4 +48,4 @@ MAV_RESULT GCS_MAVLINK::handle_servorelay_message(const mavlink_command_int_t &p
     return result;
 }
 
-#endif  // AP_SERVORELAYEVENTS_ENABLED
+#endif  // AP_MAVLINK_SERVO_RELAY_ENABLED
diff --git a/libraries/GCS_MAVLink/GCS_config.h b/libraries/GCS_MAVLink/GCS_config.h
index 28e8ddd22a..e3bb5ed7b0 100644
--- a/libraries/GCS_MAVLink/GCS_config.h
+++ b/libraries/GCS_MAVLink/GCS_config.h
@@ -61,3 +61,16 @@
 #ifndef AP_MAVLINK_MSG_MOUNT_CONTROL_ENABLED
 #define AP_MAVLINK_MSG_MOUNT_CONTROL_ENABLED HAL_GCS_ENABLED
 #endif
+
+// this is for both read and write messages:
+#ifndef AP_MAVLINK_MSG_DEVICE_OP_ENABLED
+#define AP_MAVLINK_MSG_DEVICE_OP_ENABLED HAL_GCS_ENABLED
+#endif
+
+#ifndef AP_MAVLINK_SERVO_RELAY_ENABLED
+#define AP_MAVLINK_SERVO_RELAY_ENABLED HAL_GCS_ENABLED && AP_SERVORELAYEVENTS_ENABLED
+#endif
+
+#ifndef AP_MAVLINK_MSG_SERIAL_CONTROL_ENABLED
+#define AP_MAVLINK_MSG_SERIAL_CONTROL_ENABLED HAL_GCS_ENABLED
+#endif
diff --git a/libraries/GCS_MAVLink/GCS_serial_control.cpp b/libraries/GCS_MAVLink/GCS_serial_control.cpp
index 133297dbcb..50322e2e5d 100644
--- a/libraries/GCS_MAVLink/GCS_serial_control.cpp
+++ b/libraries/GCS_MAVLink/GCS_serial_control.cpp
@@ -17,6 +17,9 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "GCS_config.h"
+
+#if AP_MAVLINK_MSG_SERIAL_CONTROL_ENABLED
 
 #include <AP_HAL/AP_HAL.h>
 #include "GCS.h"
@@ -199,3 +202,5 @@ more_data:
         goto more_data;
     }
 }
+
+#endif  // AP_MAVLINK_MSG_SERIAL_CONTROL_ENABLED