diff --git a/libraries/AP_HAL/AP_HAL_Macros.h b/libraries/AP_HAL/AP_HAL_Macros.h
index b62840006c..f0c6f1bca7 100644
--- a/libraries/AP_HAL/AP_HAL_Macros.h
+++ b/libraries/AP_HAL/AP_HAL_Macros.h
@@ -1,23 +1,11 @@
 #pragma once
 
+#include <AP_HAL/AP_HAL_Boards.h>
+
 /*
   macros to allow code to build on multiple platforms more easily
  */
 
-#ifdef __GNUC__
- #define WARN_IF_UNUSED __attribute__ ((warn_unused_result))
-#else
- #define WARN_IF_UNUSED
-#endif
-
-// use this to avoid issues between C++11 with NuttX and C++10 on
-// other platforms.
-#if !(defined(__GXX_EXPERIMENTAL_CXX0X__) || __cplusplus >= 201103L)
-# define constexpr const
-#endif
-
-#define NORETURN __attribute__ ((noreturn))
-
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL || CONFIG_HAL_BOARD == HAL_BOARD_LINUX
 /*
   allow double maths on Linux and SITL to avoid problems with system headers
diff --git a/libraries/AP_HAL/Semaphores.h b/libraries/AP_HAL/Semaphores.h
index 818a52259b..7cce91a248 100644
--- a/libraries/AP_HAL/Semaphores.h
+++ b/libraries/AP_HAL/Semaphores.h
@@ -2,6 +2,8 @@
 
 #include "AP_HAL_Namespace.h"
 
+#include <AP_Common/AP_Common.h>
+
 #define HAL_SEMAPHORE_BLOCK_FOREVER 0
 
 class AP_HAL::Semaphore {