diff --git a/libraries/AP_HAL_SITL/AP_HAL_SITL.h b/libraries/AP_HAL_SITL/AP_HAL_SITL.h
index ba063c940d..04af99ba4b 100644
--- a/libraries/AP_HAL_SITL/AP_HAL_SITL.h
+++ b/libraries/AP_HAL_SITL/AP_HAL_SITL.h
@@ -2,7 +2,7 @@
 #ifndef __AP_HAL_SITL_H__
 #define __AP_HAL_SITL_H__
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
diff --git a/libraries/AP_HAL_SITL/AnalogIn.cpp b/libraries/AP_HAL_SITL/AnalogIn.cpp
index a14f801bdb..0fc7f47bec 100644
--- a/libraries/AP_HAL_SITL/AnalogIn.cpp
+++ b/libraries/AP_HAL_SITL/AnalogIn.cpp
@@ -1,6 +1,6 @@
 /// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
 #include "AP_HAL_SITL.h"
diff --git a/libraries/AP_HAL_SITL/AnalogIn.h b/libraries/AP_HAL_SITL/AnalogIn.h
index 6b87678c2f..0de13b1dbf 100644
--- a/libraries/AP_HAL_SITL/AnalogIn.h
+++ b/libraries/AP_HAL_SITL/AnalogIn.h
@@ -2,7 +2,7 @@
 #ifndef __AP_HAL_SITL_ANALOG_IN_H__
 #define __AP_HAL_SITL_ANALOG_IN_H__
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #include "AP_HAL_SITL_Namespace.h"
 
 #define SITL_INPUT_MAX_CHANNELS 12
diff --git a/libraries/AP_HAL_SITL/HAL_SITL_Class.cpp b/libraries/AP_HAL_SITL/HAL_SITL_Class.cpp
index e1c81b41f7..c76c36911f 100644
--- a/libraries/AP_HAL_SITL/HAL_SITL_Class.cpp
+++ b/libraries/AP_HAL_SITL/HAL_SITL_Class.cpp
@@ -1,10 +1,10 @@
 /// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
-#include <AP_HAL_SITL.h>
+#include "AP_HAL_SITL.h"
 #include "AP_HAL_SITL_Namespace.h"
 #include "HAL_SITL_Class.h"
 #include "Scheduler.h"
@@ -16,8 +16,8 @@
 #include "SITL_State.h"
 #include "Util.h"
 
-#include <AP_HAL_Empty.h>
-#include <AP_HAL_Empty_Private.h>
+#include <AP_HAL_Empty/AP_HAL_Empty.h>
+#include <AP_HAL_Empty/AP_HAL_Empty_Private.h>
 
 using namespace HALSITL;
 
diff --git a/libraries/AP_HAL_SITL/HAL_SITL_Class.h b/libraries/AP_HAL_SITL/HAL_SITL_Class.h
index 007ce0a890..1a5bbe3e70 100644
--- a/libraries/AP_HAL_SITL/HAL_SITL_Class.h
+++ b/libraries/AP_HAL_SITL/HAL_SITL_Class.h
@@ -2,11 +2,11 @@
 #ifndef __AP_HAL_SITL_CLASS_H__
 #define __AP_HAL_SITL_CLASS_H__
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
-#include <AP_HAL_SITL.h>
+#include "AP_HAL_SITL.h"
 #include "AP_HAL_SITL_Namespace.h"
 #include "SITL_State.h"
 
diff --git a/libraries/AP_HAL_SITL/RCInput.cpp b/libraries/AP_HAL_SITL/RCInput.cpp
index 7365d856a6..ce0e0ff587 100644
--- a/libraries/AP_HAL_SITL/RCInput.cpp
+++ b/libraries/AP_HAL_SITL/RCInput.cpp
@@ -1,4 +1,4 @@
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
 #include "RCInput.h"
diff --git a/libraries/AP_HAL_SITL/RCInput.h b/libraries/AP_HAL_SITL/RCInput.h
index 6b4bd35d76..7c61891350 100644
--- a/libraries/AP_HAL_SITL/RCInput.h
+++ b/libraries/AP_HAL_SITL/RCInput.h
@@ -2,9 +2,9 @@
 #ifndef __AP_HAL_SITL_RCINPUT_H__
 #define __AP_HAL_SITL_RCINPUT_H__
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
-#include <AP_HAL_SITL.h>
+#include "AP_HAL_SITL.h"
 
 class HALSITL::SITLRCInput : public AP_HAL::RCInput {
 public:
diff --git a/libraries/AP_HAL_SITL/RCOutput.cpp b/libraries/AP_HAL_SITL/RCOutput.cpp
index f6b858f6ca..664f09883a 100644
--- a/libraries/AP_HAL_SITL/RCOutput.cpp
+++ b/libraries/AP_HAL_SITL/RCOutput.cpp
@@ -1,4 +1,4 @@
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
 #include "RCOutput.h"
diff --git a/libraries/AP_HAL_SITL/RCOutput.h b/libraries/AP_HAL_SITL/RCOutput.h
index c4835d5c19..a165a95c1e 100644
--- a/libraries/AP_HAL_SITL/RCOutput.h
+++ b/libraries/AP_HAL_SITL/RCOutput.h
@@ -2,9 +2,9 @@
 #ifndef __AP_HAL_SITL_RCOUTPUT_H__
 #define __AP_HAL_SITL_RCOUTPUT_H__
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
-#include <AP_HAL_SITL.h>
+#include "AP_HAL_SITL.h"
 
 class HALSITL::SITLRCOutput : public AP_HAL::RCOutput {
 public:
diff --git a/libraries/AP_HAL_SITL/SITL_State.cpp b/libraries/AP_HAL_SITL/SITL_State.cpp
index d8feaeb5b2..3b9c6be32f 100644
--- a/libraries/AP_HAL_SITL/SITL_State.cpp
+++ b/libraries/AP_HAL_SITL/SITL_State.cpp
@@ -1,10 +1,10 @@
 /// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
-#include <AP_HAL_SITL.h>
+#include "AP_HAL_SITL.h"
 #include "AP_HAL_SITL_Namespace.h"
 #include "HAL_SITL_Class.h"
 #include "UARTDriver.h"
@@ -17,7 +17,7 @@
 #include <errno.h>
 #include <sys/select.h>
 
-#include <AP_Param.h>
+#include <AP_Param/AP_Param.h>
 
 extern const AP_HAL::HAL& hal;
 
diff --git a/libraries/AP_HAL_SITL/SITL_State.h b/libraries/AP_HAL_SITL/SITL_State.h
index 11b4979b16..8c13d95dc0 100644
--- a/libraries/AP_HAL_SITL/SITL_State.h
+++ b/libraries/AP_HAL_SITL/SITL_State.h
@@ -2,11 +2,11 @@
 #ifndef __AP_HAL_SITL_STATE_H__
 #define __AP_HAL_SITL_STATE_H__
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
-#include <AP_HAL_SITL.h>
+#include "AP_HAL_SITL.h"
 #include "AP_HAL_SITL_Namespace.h"
 #include "HAL_SITL_Class.h"
 
diff --git a/libraries/AP_HAL_SITL/SITL_cmdline.cpp b/libraries/AP_HAL_SITL/SITL_cmdline.cpp
index 0acdb5abeb..6361090533 100644
--- a/libraries/AP_HAL_SITL/SITL_cmdline.cpp
+++ b/libraries/AP_HAL_SITL/SITL_cmdline.cpp
@@ -1,27 +1,27 @@
 /// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
-#include <AP_HAL_SITL.h>
+#include "AP_HAL_SITL.h"
 #include "AP_HAL_SITL_Namespace.h"
 #include "HAL_SITL_Class.h"
 #include "UARTDriver.h"
 #include <stdio.h>
 #include <signal.h>
 #include <unistd.h>
-#include <utility/getopt_cpp.h>
+#include <AP_HAL/utility/getopt_cpp.h>
 
-#include <SIM_Multicopter.h>
-#include <SIM_Helicopter.h>
-#include <SIM_Rover.h>
-#include <SIM_CRRCSim.h>
-#include <SIM_Gazebo.h>
-#include <SIM_last_letter.h>
-#include <SIM_JSBSim.h>
-#include <SIM_Tracker.h>
-#include <SIM_Balloon.h>
+#include <SITL/SIM_Multicopter.h>
+#include <SITL/SIM_Helicopter.h>
+#include <SITL/SIM_Rover.h>
+#include <SITL/SIM_CRRCSim.h>
+#include <SITL/SIM_Gazebo.h>
+#include <SITL/SIM_last_letter.h>
+#include <SITL/SIM_JSBSim.h>
+#include <SITL/SIM_Tracker.h>
+#include <SITL/SIM_Balloon.h>
 
 extern const AP_HAL::HAL& hal;
 
diff --git a/libraries/AP_HAL_SITL/Scheduler.cpp b/libraries/AP_HAL_SITL/Scheduler.cpp
index 6899bdb24f..37e74b674f 100644
--- a/libraries/AP_HAL_SITL/Scheduler.cpp
+++ b/libraries/AP_HAL_SITL/Scheduler.cpp
@@ -1,6 +1,6 @@
 /// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
 #include "AP_HAL_SITL.h"
diff --git a/libraries/AP_HAL_SITL/Scheduler.h b/libraries/AP_HAL_SITL/Scheduler.h
index 1e4be6c060..cc0936e571 100644
--- a/libraries/AP_HAL_SITL/Scheduler.h
+++ b/libraries/AP_HAL_SITL/Scheduler.h
@@ -2,7 +2,7 @@
 #ifndef __AP_HAL_SITL_SCHEDULER_H__
 #define __AP_HAL_SITL_SCHEDULER_H__
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 #include "AP_HAL_SITL_Namespace.h"
 #include <sys/time.h>
diff --git a/libraries/AP_HAL_SITL/Storage.cpp b/libraries/AP_HAL_SITL/Storage.cpp
index 0f936b8ba4..9794fcac27 100644
--- a/libraries/AP_HAL_SITL/Storage.cpp
+++ b/libraries/AP_HAL_SITL/Storage.cpp
@@ -1,4 +1,4 @@
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
 #include <assert.h>
diff --git a/libraries/AP_HAL_SITL/Storage.h b/libraries/AP_HAL_SITL/Storage.h
index 74801e3141..23c1436cbb 100644
--- a/libraries/AP_HAL_SITL/Storage.h
+++ b/libraries/AP_HAL_SITL/Storage.h
@@ -3,7 +3,7 @@
 #ifndef __AP_HAL_SITL_STORAGE_H__
 #define __AP_HAL_SITL_STORAGE_H__
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #include "AP_HAL_SITL_Namespace.h"
 
 class HALSITL::SITLEEPROMStorage : public AP_HAL::Storage {
diff --git a/libraries/AP_HAL_SITL/UARTDriver.cpp b/libraries/AP_HAL_SITL/UARTDriver.cpp
index 49715ce86d..f5e71b1517 100644
--- a/libraries/AP_HAL_SITL/UARTDriver.cpp
+++ b/libraries/AP_HAL_SITL/UARTDriver.cpp
@@ -17,7 +17,7 @@
 //
 //      Copyright (c) 2010 Michael Smith. All rights reserved.
 //
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
 #include <limits.h>
@@ -26,7 +26,7 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <stdarg.h>
-#include <AP_Math.h>
+#include <AP_Math/AP_Math.h>
 
 #include <errno.h>
 #include <sys/ioctl.h>
diff --git a/libraries/AP_HAL_SITL/UARTDriver.h b/libraries/AP_HAL_SITL/UARTDriver.h
index 7a67c17938..8f759ee48f 100644
--- a/libraries/AP_HAL_SITL/UARTDriver.h
+++ b/libraries/AP_HAL_SITL/UARTDriver.h
@@ -2,7 +2,7 @@
 
 #ifndef __AP_HAL_SITL_UART_DRIVER_H__
 #define __AP_HAL_SITL_UART_DRIVER_H__
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
 #include <stdint.h>
diff --git a/libraries/AP_HAL_SITL/Util.h b/libraries/AP_HAL_SITL/Util.h
index eedc57921d..cd18517032 100644
--- a/libraries/AP_HAL_SITL/Util.h
+++ b/libraries/AP_HAL_SITL/Util.h
@@ -2,7 +2,7 @@
 #ifndef __AP_HAL_SITL_UTIL_H__
 #define __AP_HAL_SITL_UTIL_H__
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #include "AP_HAL_SITL_Namespace.h"
 
 class HALSITL::SITLUtil : public AP_HAL::Util {
diff --git a/libraries/AP_HAL_SITL/sitl_barometer.cpp b/libraries/AP_HAL_SITL/sitl_barometer.cpp
index 8fd76f1c56..d20a9c2705 100644
--- a/libraries/AP_HAL_SITL/sitl_barometer.cpp
+++ b/libraries/AP_HAL_SITL/sitl_barometer.cpp
@@ -6,8 +6,8 @@
   Andrew Tridgell November 2011
  */
 
-#include <AP_HAL.h>
-#include <AP_Math.h>
+#include <AP_HAL/AP_HAL.h>
+#include <AP_Math/AP_Math.h>
 
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
diff --git a/libraries/AP_HAL_SITL/sitl_compass.cpp b/libraries/AP_HAL_SITL/sitl_compass.cpp
index db96461f85..8d5fa5c200 100644
--- a/libraries/AP_HAL_SITL/sitl_compass.cpp
+++ b/libraries/AP_HAL_SITL/sitl_compass.cpp
@@ -6,14 +6,14 @@
   Andrew Tridgell November 2011
  */
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
-#include <AP_HAL_SITL.h>
+#include "AP_HAL_SITL.h"
 #include "AP_HAL_SITL_Namespace.h"
 #include "HAL_SITL_Class.h"
 
-#include <AP_Math.h>
+#include <AP_Math/AP_Math.h>
 #include "../AP_Compass/AP_Compass.h"
 #include "../AP_Declination/AP_Declination.h"
 #include "../SITL/SITL.h"
diff --git a/libraries/AP_HAL_SITL/sitl_gps.cpp b/libraries/AP_HAL_SITL/sitl_gps.cpp
index 164ff3048e..6fbca498fc 100644
--- a/libraries/AP_HAL_SITL/sitl_gps.cpp
+++ b/libraries/AP_HAL_SITL/sitl_gps.cpp
@@ -7,14 +7,14 @@
   Andrew Tridgell November 2011
  */
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
-#include <AP_HAL_SITL.h>
+#include "AP_HAL_SITL.h"
 #include "AP_HAL_SITL_Namespace.h"
 #include "HAL_SITL_Class.h"
 
-#include <AP_Math.h>
+#include <AP_Math/AP_Math.h>
 #include "../SITL/SITL.h"
 #include "Scheduler.h"
 #include "UARTDriver.h"
diff --git a/libraries/AP_HAL_SITL/sitl_ins.cpp b/libraries/AP_HAL_SITL/sitl_ins.cpp
index aba22664a3..2f77957cfd 100644
--- a/libraries/AP_HAL_SITL/sitl_ins.cpp
+++ b/libraries/AP_HAL_SITL/sitl_ins.cpp
@@ -6,22 +6,22 @@
   Andrew Tridgell November 2011
  */
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 
-#include <AP_HAL_SITL.h>
+#include "AP_HAL_SITL.h"
 #include "AP_HAL_SITL_Namespace.h"
 #include "HAL_SITL_Class.h"
 
-#include <AP_Math.h>
+#include <AP_Math/AP_Math.h>
 #include "../AP_Compass/AP_Compass.h"
 #include "../AP_Declination/AP_Declination.h"
 #include "../AP_RangeFinder/AP_RangeFinder.h"
 #include "../SITL/SITL.h"
 #include "Scheduler.h"
-#include <AP_Math.h>
+#include <AP_Math/AP_Math.h>
 #include "../AP_ADC/AP_ADC.h"
-#include <SITL_State.h>
+#include "SITL_State.h"
 #include <fenv.h>
 
 extern const AP_HAL::HAL& hal;
diff --git a/libraries/AP_HAL_SITL/sitl_optical_flow.cpp b/libraries/AP_HAL_SITL/sitl_optical_flow.cpp
index ee273a7e48..77eb890876 100644
--- a/libraries/AP_HAL_SITL/sitl_optical_flow.cpp
+++ b/libraries/AP_HAL_SITL/sitl_optical_flow.cpp
@@ -6,8 +6,8 @@
   Andrew Tridgell November 2011
  */
 
-#include <AP_HAL.h>
-#include <AP_Math.h>
+#include <AP_HAL/AP_HAL.h>
+#include <AP_Math/AP_Math.h>
 
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL