diff --git a/src/codecs/music_timidity.c b/src/codecs/music_timidity.c
index 27d95751..5bbb93ed 100644
--- a/src/codecs/music_timidity.c
+++ b/src/codecs/music_timidity.c
@@ -45,9 +45,9 @@ static void TIMIDITY_Delete(void *context);
 /* Config file should contain any other directory that needs
  * to be added to the search path. The library adds the path
  * of the config file to its search path, too. */
-#if defined(__WIN32__)
+#if defined(SDL_PLATFORM_WIN32)
 # define TIMIDITY_CFG           "C:\\TIMIDITY\\TIMIDITY.CFG"
-#elif defined(__OS2__)
+#elif defined(SDL_PLATFORM_OS2)
 # define TIMIDITY_CFG           "C:\\TIMIDITY\\TIMIDITY.CFG"
 # define TIMIDITY_CFG_ETC       "/@unixroot/etc/timidity/timidity.cfg"
 #else  /* unix: */
diff --git a/src/codecs/native_midi/native_midi_haiku.cpp b/src/codecs/native_midi/native_midi_haiku.cpp
index d26130d4..531bbe7f 100644
--- a/src/codecs/native_midi/native_midi_haiku.cpp
+++ b/src/codecs/native_midi/native_midi_haiku.cpp
@@ -20,7 +20,7 @@
 */
 #include <SDL3/SDL_platform.h>
 
-#ifdef __HAIKU__
+#ifdef SDL_PLATFORM_HAIKU
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -292,4 +292,4 @@ const char* native_midi_error(void)
   return lasterr;
 }
 
-#endif /* __HAIKU__ */
+#endif /* SDL_PLATFORM_HAIKU */
diff --git a/src/codecs/native_midi/native_midi_macosx.c b/src/codecs/native_midi/native_midi_macosx.c
index 44fd1444..8df64cff 100644
--- a/src/codecs/native_midi/native_midi_macosx.c
+++ b/src/codecs/native_midi/native_midi_macosx.c
@@ -21,7 +21,7 @@
 
 #include <SDL3/SDL_platform.h>
 
-#if __MACOS__
+#ifdef SDL_PLATFORM_MACOS
 
 /* Mac OS X 10.6+, using Core MIDI. */
 
diff --git a/src/codecs/native_midi/native_midi_win32.c b/src/codecs/native_midi/native_midi_win32.c
index 914e32ae..d4b6b01e 100644
--- a/src/codecs/native_midi/native_midi_win32.c
+++ b/src/codecs/native_midi/native_midi_win32.c
@@ -22,7 +22,7 @@
 
 /* everything below is currently one very big bad hack ;) Proff */
 
-#if __WIN32__
+#ifdef SDL_PLATFORM_WIN32
 #define WIN32_LEAN_AND_MEAN
 
 #include <windows.h>
diff --git a/src/codecs/timidity/common.c b/src/codecs/timidity/common.c
index e9134aaa..e79e3179 100644
--- a/src/codecs/timidity/common.c
+++ b/src/codecs/timidity/common.c
@@ -13,7 +13,7 @@
 #include "options.h"
 #include "common.h"
 
-#if defined(__WIN32__) || defined(__OS2__)
+#if defined(SDL_PLATFORM_WIN32) || defined(SDL_PLATFORM_OS2)
 #define CHAR_DIRSEP '\\'
 #define is_dirsep(c) ((c) == '/' || (c) == '\\')
 #define is_abspath(p) ((p)[0] == '/' || (p)[0] == '\\' || ((p)[0] && (p)[1] == ':'))