diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow.h b/libraries/AP_OpticalFlow/AP_OpticalFlow.h
index b5751d7351..d071436f8c 100644
--- a/libraries/AP_OpticalFlow/AP_OpticalFlow.h
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow.h
@@ -14,19 +14,7 @@
  */
 #pragma once
 
-#include <AP_HAL/AP_HAL_Boards.h>
-
-#ifndef AP_OPTICALFLOW_ENABLED
-#define AP_OPTICALFLOW_ENABLED 1
-#endif
-
-#ifndef HAL_MSP_OPTICALFLOW_ENABLED
-#define HAL_MSP_OPTICALFLOW_ENABLED (AP_OPTICALFLOW_ENABLED && (HAL_MSP_ENABLED && !HAL_MINIMIZE_FEATURES))
-#endif
-
-#ifndef AP_OPTICALFLOW_SITL_ENABLED
-#define AP_OPTICALFLOW_SITL_ENABLED AP_SIM_ENABLED
-#endif
+#include "AP_OpticalFlow_config.h"
 
 #if AP_OPTICALFLOW_ENABLED
 
diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow_Backend.h b/libraries/AP_OpticalFlow/AP_OpticalFlow_Backend.h
index 059e5b92d1..f0c5b3096e 100644
--- a/libraries/AP_OpticalFlow/AP_OpticalFlow_Backend.h
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow_Backend.h
@@ -20,6 +20,8 @@
 
 #include "AP_OpticalFlow.h"
 
+#include <AP_HAL/Semaphores.h>
+
 class OpticalFlow_backend
 {
     friend class AP_OpticalFlow;
diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow_CXOF.h b/libraries/AP_OpticalFlow/AP_OpticalFlow_CXOF.h
index 2cb8716bf8..d76205f46c 100644
--- a/libraries/AP_OpticalFlow/AP_OpticalFlow_CXOF.h
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow_CXOF.h
@@ -1,14 +1,10 @@
 #pragma once
 
-#include "AP_OpticalFlow.h"
-
-#ifndef AP_OPTICALFLOW_CXOF_ENABLED
-#define AP_OPTICALFLOW_CXOF_ENABLED AP_OPTICALFLOW_ENABLED
-#endif
+#include "AP_OpticalFlow_config.h"
 
 #if AP_OPTICALFLOW_CXOF_ENABLED
 
-#include <AP_HAL/utility/OwnPtr.h>
+#include "AP_OpticalFlow_Backend.h"
 
 class AP_OpticalFlow_CXOF : public OpticalFlow_backend
 {
diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow_HereFlow.h b/libraries/AP_OpticalFlow/AP_OpticalFlow_HereFlow.h
index fa340584ff..8b61a87bf7 100644
--- a/libraries/AP_OpticalFlow/AP_OpticalFlow_HereFlow.h
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow_HereFlow.h
@@ -1,13 +1,10 @@
 #pragma once
 
-#include "AP_OpticalFlow.h"
-
-#ifndef AP_OPTICALFLOW_HEREFLOW_ENABLED
-#define AP_OPTICALFLOW_HEREFLOW_ENABLED (AP_OPTICALFLOW_ENABLED && HAL_ENABLE_DRONECAN_DRIVERS)
-#endif
+#include "AP_OpticalFlow_config.h"
 
 #if AP_OPTICALFLOW_HEREFLOW_ENABLED
 
+#include "AP_OpticalFlow_Backend.h"
 #include <AP_DroneCAN/AP_DroneCAN.h>
 
 class AP_OpticalFlow_HereFlow : public OpticalFlow_backend {
diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow_MAV.h b/libraries/AP_OpticalFlow/AP_OpticalFlow_MAV.h
index 3784e4dc76..b9f0f6e9ad 100644
--- a/libraries/AP_OpticalFlow/AP_OpticalFlow_MAV.h
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow_MAV.h
@@ -1,13 +1,10 @@
 #pragma once
 
-#include "AP_OpticalFlow.h"
-
-#ifndef AP_OPTICALFLOW_MAV_ENABLED
-#define AP_OPTICALFLOW_MAV_ENABLED AP_OPTICALFLOW_ENABLED
-#endif
+#include "AP_OpticalFlow_config.h"
 
 #if AP_OPTICALFLOW_MAV_ENABLED
 
+#include "AP_OpticalFlow_Backend.h"
 #include <AP_HAL/utility/OwnPtr.h>
 
 class AP_OpticalFlow_MAV : public OpticalFlow_backend
diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow_Onboard.cpp b/libraries/AP_OpticalFlow/AP_OpticalFlow_Onboard.cpp
index a6e46b928e..00cf389b23 100644
--- a/libraries/AP_OpticalFlow/AP_OpticalFlow_Onboard.cpp
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow_Onboard.cpp
@@ -12,17 +12,15 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#include "AP_OpticalFlow_Onboard.h"
+
+#include "AP_OpticalFlow_config.h"
 
 #if AP_OPTICALFLOW_ONBOARD_ENABLED
 
+#include "AP_OpticalFlow_Onboard.h"
+
 #include <AP_HAL/AP_HAL.h>
 
-#include "AP_OpticalFlow.h"
-
-#if CONFIG_HAL_BOARD == HAL_BOARD_LINUX &&\
-    CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_BEBOP
-
 #ifndef OPTICALFLOW_ONBOARD_DEBUG
 #define OPTICALFLOW_ONBOARD_DEBUG 0
 #endif
@@ -95,6 +93,4 @@ void AP_OpticalFlow_Onboard::update()
 #endif
 }
 
-#endif
-
 #endif  // AP_OPTICALFLOW_ONBOARD_ENABLED
diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow_Onboard.h b/libraries/AP_OpticalFlow/AP_OpticalFlow_Onboard.h
index 3d21d82ed2..2950062d93 100644
--- a/libraries/AP_OpticalFlow/AP_OpticalFlow_Onboard.h
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow_Onboard.h
@@ -14,18 +14,11 @@
  */
 #pragma once
 
-#include <AP_OpticalFlow/AP_OpticalFlow.h>
-
-#ifndef AP_OPTICALFLOW_ONBOARD_ENABLED
-#define AP_OPTICALFLOW_ONBOARD_ENABLED AP_OPTICALFLOW_ENABLED
-#endif
+#include "AP_OpticalFlow_config.h"
 
 #if AP_OPTICALFLOW_ONBOARD_ENABLED
 
-#include <AP_AHRS/AP_AHRS.h>
-#include <AP_Math/AP_Math.h>
-#include <AP_NavEKF2/AP_NavEKF2.h>
-#include <AP_NavEKF3/AP_NavEKF3.h>
+#include <AP_OpticalFlow/AP_OpticalFlow_Backend.h>
 
 #include "AP_OpticalFlow.h"
 
diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow_PX4Flow.cpp b/libraries/AP_OpticalFlow/AP_OpticalFlow_PX4Flow.cpp
index 4b051250af..0f72760d02 100644
--- a/libraries/AP_OpticalFlow/AP_OpticalFlow_PX4Flow.cpp
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow_PX4Flow.cpp
@@ -16,10 +16,12 @@
   driver for PX4Flow optical flow sensor
  */
 
-#include "AP_OpticalFlow_PX4Flow.h"
+#include "AP_OpticalFlow_config.h"
 
 #if AP_OPTICALFLOW_PX4FLOW_ENABLED
 
+#include "AP_OpticalFlow_PX4Flow.h"
+
 #include <AP_HAL/AP_HAL.h>
 #include <AP_Math/crc.h>
 #include <AP_AHRS/AP_AHRS.h>
diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow_PX4Flow.h b/libraries/AP_OpticalFlow/AP_OpticalFlow_PX4Flow.h
index c5c22b6de2..98e579b3e1 100644
--- a/libraries/AP_OpticalFlow/AP_OpticalFlow_PX4Flow.h
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow_PX4Flow.h
@@ -1,13 +1,10 @@
 #pragma once
 
-#include "AP_OpticalFlow.h"
-
-#ifndef AP_OPTICALFLOW_PX4FLOW_ENABLED
-#define AP_OPTICALFLOW_PX4FLOW_ENABLED AP_OPTICALFLOW_ENABLED
-#endif
+#include "AP_OpticalFlow_config.h"
 
 #if AP_OPTICALFLOW_PX4FLOW_ENABLED
 
+#include "AP_OpticalFlow_Backend.h"
 #include <AP_HAL/utility/OwnPtr.h>
 
 class AP_OpticalFlow_PX4Flow : public OpticalFlow_backend
diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow_Pixart.cpp b/libraries/AP_OpticalFlow/AP_OpticalFlow_Pixart.cpp
index 96ca4f9425..1095e44227 100644
--- a/libraries/AP_OpticalFlow/AP_OpticalFlow_Pixart.cpp
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow_Pixart.cpp
@@ -20,10 +20,12 @@
   timing for register reads and writes is critical
  */
 
-#include "AP_OpticalFlow_Pixart.h"
+#include "AP_OpticalFlow_config.h"
 
 #if AP_OPTICALFLOW_PIXART_ENABLED
 
+#include "AP_OpticalFlow_Pixart.h"
+
 #include <AP_HAL/AP_HAL.h>
 #include <AP_Math/crc.h>
 #include <AP_AHRS/AP_AHRS.h>
diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow_Pixart.h b/libraries/AP_OpticalFlow/AP_OpticalFlow_Pixart.h
index d1720eea72..2aeb5dd8e8 100644
--- a/libraries/AP_OpticalFlow/AP_OpticalFlow_Pixart.h
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow_Pixart.h
@@ -1,13 +1,11 @@
 #pragma once
 
-#include "AP_OpticalFlow.h"
-
-#ifndef AP_OPTICALFLOW_PIXART_ENABLED
-#define AP_OPTICALFLOW_PIXART_ENABLED AP_OPTICALFLOW_ENABLED
-#endif
+#include "AP_OpticalFlow_config.h"
 
 #if AP_OPTICALFLOW_PIXART_ENABLED
 
+#include "AP_OpticalFlow_Backend.h"
+
 #include <AP_HAL/utility/OwnPtr.h>
 
 class AP_OpticalFlow_Pixart : public OpticalFlow_backend
diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow_SITL.h b/libraries/AP_OpticalFlow/AP_OpticalFlow_SITL.h
index e54cdc8e9c..a9e816aaac 100644
--- a/libraries/AP_OpticalFlow/AP_OpticalFlow_SITL.h
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow_SITL.h
@@ -1,9 +1,11 @@
 #pragma once
 
-#include "AP_OpticalFlow.h"
+#include "AP_OpticalFlow_config.h"
 
 #if AP_OPTICALFLOW_SITL_ENABLED
 
+#include "AP_OpticalFlow.h"
+
 class AP_OpticalFlow_SITL : public OpticalFlow_backend
 {
 public:
diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow_UPFLOW.h b/libraries/AP_OpticalFlow/AP_OpticalFlow_UPFLOW.h
index 64bec165ee..c39e14359e 100644
--- a/libraries/AP_OpticalFlow/AP_OpticalFlow_UPFLOW.h
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow_UPFLOW.h
@@ -1,13 +1,10 @@
 #pragma once
 
-#include "AP_OpticalFlow.h"
-
-#ifndef AP_OPTICALFLOW_UPFLOW_ENABLED
-#define AP_OPTICALFLOW_UPFLOW_ENABLED AP_OPTICALFLOW_ENABLED
-#endif
+#include "AP_OpticalFlow_config.h"
 
 #if AP_OPTICALFLOW_UPFLOW_ENABLED
 
+#include "AP_OpticalFlow_Backend.h"
 #include <AP_HAL/utility/OwnPtr.h>
 
 class AP_OpticalFlow_UPFLOW : public OpticalFlow_backend
diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow_config.h b/libraries/AP_OpticalFlow/AP_OpticalFlow_config.h
new file mode 100644
index 0000000000..1d2eb4cf99
--- /dev/null
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow_config.h
@@ -0,0 +1,49 @@
+#pragma once
+
+#include <AP_HAL/AP_HAL_Boards.h>
+#include <AP_MSP/AP_MSP_config.h>
+#include <GCS_MAVLink/GCS_config.h>
+
+#ifndef AP_OPTICALFLOW_ENABLED
+#define AP_OPTICALFLOW_ENABLED 1
+#endif
+
+#ifndef AP_OPTICALFLOW_BACKEND_DEFAULT_ENABLED
+#define AP_OPTICALFLOW_BACKEND_DEFAULT_ENABLED AP_OPTICALFLOW_ENABLED
+#endif
+
+#ifndef AP_OPTICALFLOW_CXOF_ENABLED
+#define AP_OPTICALFLOW_CXOF_ENABLED AP_OPTICALFLOW_BACKEND_DEFAULT_ENABLED
+#endif
+
+#ifndef AP_OPTICALFLOW_HEREFLOW_ENABLED
+#define AP_OPTICALFLOW_HEREFLOW_ENABLED (AP_OPTICALFLOW_BACKEND_DEFAULT_ENABLED && HAL_ENABLE_DRONECAN_DRIVERS)
+#endif
+
+#ifndef AP_OPTICALFLOW_MAV_ENABLED
+#define AP_OPTICALFLOW_MAV_ENABLED (AP_OPTICALFLOW_BACKEND_DEFAULT_ENABLED && HAL_GCS_ENABLED)
+#endif
+
+#ifndef HAL_MSP_OPTICALFLOW_ENABLED
+#define HAL_MSP_OPTICALFLOW_ENABLED (AP_OPTICALFLOW_BACKEND_DEFAULT_ENABLED && (HAL_MSP_ENABLED && !HAL_MINIMIZE_FEATURES))
+#endif
+
+#ifndef AP_OPTICALFLOW_ONBOARD_ENABLED
+#define AP_OPTICALFLOW_ONBOARD_ENABLED (AP_OPTICALFLOW_BACKEND_DEFAULT_ENABLED && CONFIG_HAL_BOARD == HAL_BOARD_LINUX && CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_BEBOP)
+#endif
+
+#ifndef AP_OPTICALFLOW_PIXART_ENABLED
+#define AP_OPTICALFLOW_PIXART_ENABLED AP_OPTICALFLOW_BACKEND_DEFAULT_ENABLED
+#endif
+
+#ifndef AP_OPTICALFLOW_PX4FLOW_ENABLED
+#define AP_OPTICALFLOW_PX4FLOW_ENABLED AP_OPTICALFLOW_BACKEND_DEFAULT_ENABLED
+#endif
+
+#ifndef AP_OPTICALFLOW_SITL_ENABLED
+#define AP_OPTICALFLOW_SITL_ENABLED (AP_OPTICALFLOW_BACKEND_DEFAULT_ENABLED && AP_SIM_ENABLED)
+#endif
+
+#ifndef AP_OPTICALFLOW_UPFLOW_ENABLED
+#define AP_OPTICALFLOW_UPFLOW_ENABLED AP_OPTICALFLOW_BACKEND_DEFAULT_ENABLED
+#endif