diff --git a/hal.h b/hal.h
--- a/hal.h
+++ b/hal.h
@@ -59,10 +59,6 @@ extern const DriverDesc _music_driver_de
 extern const HalMusicDriver _bemidi_music_driver;
 #endif
 
-#if defined(__OS2__)
-extern const HalMusicDriver _os2_music_driver;
-#endif
-
 extern const HalVideoDriver _dedicated_video_driver;
 
 enum DriverType {
diff --git a/os2.c b/os2.c
--- a/os2.c
+++ b/os2.c
@@ -1,13 +1,10 @@
 #include "stdafx.h"
 #include "openttd.h"
 #include "variables.h"
-#include "window.h"
 #include "string.h"
 #include "table/strings.h"
-#include "hal.h"
 #include "gfx.h"
 #include "gui.h"
-#include "saveload.h"
 #include "functions.h"
 #include "macros.h"
 
@@ -22,19 +19,13 @@
 #include <dos.h>
 
 #define INCL_DOS
-#define INCL_OS2MM
 #define INCL_WIN
 #define INCL_WINCLIPBOARD
 
 #include <os2.h>
-#include <os2me.h>
 
 #include <i86.h>
 
-#if defined(WITH_SDL)
-#include <SDL.h>
-#endif
-
 #include "sound/null_s.h"
 #include "sound/sdl_s.h"