diff --git a/BasiliskII/src/SDL/audio_sdl3.cpp b/BasiliskII/src/SDL/audio_sdl3.cpp
index 1a27f721..b28757c9 100644
--- a/BasiliskII/src/SDL/audio_sdl3.cpp
+++ b/BasiliskII/src/SDL/audio_sdl3.cpp
@@ -1,5 +1,5 @@
 /*
- *  audio_sdl.cpp - Audio support, SDL implementation
+ *  audio_sdl3.cpp - Audio support, SDL implementation
  *
  *  Basilisk II (C) 1997-2008 Christian Bauer
  *
@@ -33,6 +33,7 @@
 
 #if SDL_VERSION_ATLEAST(3, 0, 0)
 #include <SDL_init.h>
+#include <queue>
 
 #define DEBUG 0
 #include "debug.h"
@@ -57,10 +58,11 @@ static int speaker_volume = MAC_MAX_VOLUME;
 static bool main_mute = false;
 static bool speaker_mute = false;
 
+volatile static bool playing_startup, exit_startup;
 SDL_AudioSpec audio_spec;
 
 // Prototypes
-static void SDLCALL stream_func(void *arg, SDL_AudioStream *stream, int stream_len);
+static void SDLCALL stream_func(void *arg, SDL_AudioStream *stream, int additional_amount, int total_amount);
 static int get_audio_volume();
 
 
@@ -161,6 +163,10 @@ void AudioInit(void)
 
 static void close_audio(void)
 {
+	exit_startup = true;
+	while (playing_startup)
+		SDL_Delay(10);
+	exit_startup = false;
 	// Close audio device
 	SDL_QuitSubSystem(SDL_INIT_AUDIO);
 	audio_open = false;
@@ -198,8 +204,8 @@ void audio_exit_stream()
 /*
  *  Streaming function
  */
-#include <queue>
-static void SDLCALL stream_func(void *, SDL_AudioStream *stream, int stream_len)
+
+static void SDLCALL stream_func(void *, SDL_AudioStream *stream, int stream_len, int /*total_amount*/)
 {
 	static std::queue<uint8> q;
 	if (AudioStatus.num_sources) {
@@ -358,23 +364,25 @@ static int play_startup(void *arg) {
 	SDL_AudioSpec wav_spec;
 	Uint8 *wav_buffer;
 	Uint32 wav_length;
-	if (!SDL_LoadWAV("startup.wav", &wav_spec, &wav_buffer, &wav_length)) {
+	if (!playing_startup && !SDL_LoadWAV("startup.wav", &wav_spec, &wav_buffer, &wav_length)) {
 		SDL_AudioStream *stream = SDL_OpenAudioDeviceStream(SDL_AUDIO_DEVICE_DEFAULT_OUTPUT, &wav_spec, NULL, NULL);
 		if (stream) {
 			SDL_ResumeAudioDevice(SDL_GetAudioStreamDevice(stream));
 			SDL_PutAudioStreamData(stream, wav_buffer, wav_length);
-			while (SDL_GetAudioStreamAvailable(stream)) SDL_Delay(10);
-			SDL_Delay(500);
+			playing_startup = true;
+			while (!exit_startup && SDL_GetAudioStreamAvailable(stream)) SDL_Delay(10);
+			if (!exit_startup) SDL_Delay(500);
 			SDL_DestroyAudioStream(stream);
 		}
 		else printf("play_startup: Audio driver failed to initialize\n");
 		SDL_free(wav_buffer);
+		playing_startup = false;
 	}
 	return 0;
 }
 
 void PlayStartupSound() {
-	SDL_CreateThread(play_startup, "", NULL);
+	SDL_CreateThread(play_startup, "play_startup", NULL);
 }
 
 #endif	// SDL_VERSION_ATLEAST
diff --git a/BasiliskII/src/SDL/video_sdl3.cpp b/BasiliskII/src/SDL/video_sdl3.cpp
index 920f863c..83ba0c3f 100644
--- a/BasiliskII/src/SDL/video_sdl3.cpp
+++ b/BasiliskII/src/SDL/video_sdl3.cpp
@@ -1,5 +1,5 @@
 /*
- *  video_sdl2.cpp - Video/graphics emulation, SDL 2.x specific stuff
+ *  video_sdl3.cpp - Video/graphics emulation, SDL 3.x specific stuff
  *
  *  Basilisk II (C) 1997-2008 Christian Bauer
  *
@@ -50,7 +50,7 @@
 #include <vector>
 #include <string>
 
-#ifdef __MACOSX__
+#ifdef __MACOS__
 #include "utils_macosx.h"
 #endif
 
@@ -96,7 +96,7 @@ static int display_type = DISPLAY_WINDOW;			// See enum above
 #endif
 
 // Constants
-#if defined(__MACOSX__) || defined(WIN32)
+#if defined(__MACOS__) || defined(WIN32)
 const char KEYCODE_FILE_NAME[] = "keycodes";
 const char KEYCODE_FILE_NAME2[] = "BasiliskII_keycodes";
 #else
@@ -742,7 +742,7 @@ static SDL_Surface * init_sdl_video(int width, int height, int depth, Uint32 fla
 		}
 	}
 	
-#ifdef __MACOSX__
+#ifdef __MACOS__
 	if (MetalIsAvailable()) window_flags |= SDL_WINDOW_METAL;
 #endif
 	
@@ -777,7 +777,7 @@ static SDL_Surface * init_sdl_video(int width, int height, int depth, Uint32 fla
 		else {
 #ifdef WIN32
 			SDL_SetHint(SDL_HINT_RENDER_DRIVER, "software");
-#elif defined(__MACOSX__)
+#elif defined(__MACOS__)
 			SDL_SetHint(SDL_HINT_RENDER_DRIVER, window_flags & SDL_WINDOW_METAL ? "metal" : "opengl");
 #else
 			SDL_SetHint(SDL_HINT_RENDER_DRIVER, "opengl");
@@ -1672,14 +1672,14 @@ static void do_toggle_fullscreen(void)
 			int m = get_mag_rate();
 			SDL_SetWindowSize(sdl_window, m * VIDEO_MODE_X, m * VIDEO_MODE_Y);
 			//SDL_SetWindowGrab(sdl_window, SDL_FALSE);
-#ifndef __MACOSX__
+#ifndef __MACOS__
 			SDL_SetWindowPosition(sdl_window, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
 #endif
 		} else {
 			display_type = DISPLAY_SCREEN;
 			SDL_SetWindowFullscreen(sdl_window, SDL_TRUE);
 			//SDL_SetWindowGrab(sdl_window, SDL_TRUE);
-#ifdef __MACOSX__
+#ifdef __MACOS__
 			set_menu_bar_visible_osx(false);
 #endif
 		}
@@ -1718,7 +1718,7 @@ static void do_toggle_fullscreen(void)
 
 static bool is_fullscreen(SDL_Window * window)
 {
-#ifdef __MACOSX__
+#ifdef __MACOS__
 	// On OSX, SDL, at least as of 2.0.5 (and possibly beyond), does not always
 	// report changes to fullscreen via the SDL_WINDOW_FULLSCREEN flag.
 	// (Example: https://bugzilla.libsdl.org/show_bug.cgi?id=3766 , which
diff --git a/BasiliskII/src/Unix/configure.ac b/BasiliskII/src/Unix/configure.ac
index c3d6d3d5..27bf238c 100755
--- a/BasiliskII/src/Unix/configure.ac
+++ b/BasiliskII/src/Unix/configure.ac
@@ -333,7 +333,7 @@ if [[ "x$WANT_SDL" = "xyes" ]]; then
     if [[ "x$TEMP_WANT_SDL_VERSION_MAJOR" = "x3" ]]; then
       PKG_CHECK_MODULES([sdl3], [sdl3 >= 3.0], [
         CXXFLAGS="$CXXFLAGS $sdl3_CFLAGS"
-        CXXFLAGS+=`echo $sdl3_CFLAGS | sed -e 's/\(-I.*include\)/\1\/SDL3/'`
+        CXXFLAGS+=`echo " $sdl3_CFLAGS" | sed -e 's/\(-I.*include\)/\1\/SDL3/'`
         LIBS="$LIBS $sdl3_LIBS"
         WANT_SDL_VERSION_MAJOR=3
       ], [
diff --git a/BasiliskII/src/Unix/main_unix.cpp b/BasiliskII/src/Unix/main_unix.cpp
index a18ee273..4ed4dcf7 100755
--- a/BasiliskII/src/Unix/main_unix.cpp
+++ b/BasiliskII/src/Unix/main_unix.cpp
@@ -29,6 +29,9 @@
 #ifdef USE_SDL
 # include <SDL.h>
 # include <SDL_main.h>
+#if !SDL_VERSION_ATLEAST(3, 0, 0)
+#define __MACOS__	__MACOSX__
+#endif
 #endif
 
 #ifndef USE_SDL_VIDEO
@@ -43,7 +46,7 @@
 # include <sys/mman.h>
 #endif
 
-#if __MACOSX__
+#if __MACOS__
 # include "utils_macosx.h"
 #endif
 
@@ -568,7 +571,7 @@ int main(int argc, char **argv)
 	}
 	atexit(SDL_Quit);
 
-#if __MACOSX__ && SDL_VERSION_ATLEAST(2,0,0)
+#if __MACOS__ && SDL_VERSION_ATLEAST(2,0,0)
 	// On Mac OS X hosts, SDL2 will create its own menu bar.  This is mostly OK,
 	// except that it will also install keyboard shortcuts, such as Command + Q,
 	// which can interfere with keyboard shortcuts in the guest OS.
@@ -692,7 +695,7 @@ int main(int argc, char **argv)
 	ROMBaseMac = Host2MacAddr(ROMBaseHost);
 #endif
 
-#if __MACOSX__
+#if __MACOS__
 	extern void set_current_directory();
 	set_current_directory();
 #endif
diff --git a/BasiliskII/src/Windows/configure.ac b/BasiliskII/src/Windows/configure.ac
index b2286f7a..b747bcaf 100644
--- a/BasiliskII/src/Windows/configure.ac
+++ b/BasiliskII/src/Windows/configure.ac
@@ -549,6 +549,7 @@ CPUSRCS="../uae_cpu/basilisk_glue.cpp ../uae_cpu/memory.cpp ../uae_cpu/newcpu.cp
 dnl We really want SDL for now
 if [[ "x$WANT_SDL_VERSION_MAJOR" = "x3" ]]; then
   SDL_CFLAGS=`pkg-config sdl3 --cflags`
+  SDL_CFLAGS+=`echo " $SDL_CFLAGS" | sed -e 's/\(-I.*include\)/\1\/SDL3/'`
   SDL_LIBS=`pkg-config sdl3 --libs | sed -e 's/-lSDL3/-lSDL3.dll/'`
 else
   SDL_CFLAGS=`sdl2-config --cflags`
diff --git a/BasiliskII/src/bincue.cpp b/BasiliskII/src/bincue.cpp
index 1a7efb84..b79ddb47 100644
--- a/BasiliskII/src/bincue.cpp
+++ b/BasiliskII/src/bincue.cpp
@@ -522,8 +522,11 @@ void close_bincue(void *fh)
 	if (cs && player) {
 		free(cs);
 #ifdef USE_SDL_AUDIO
+#if !SDL_VERSION_ATLEAST(3, 0, 0)
+#define SDL_DestroyAudioStream	SDL_FreeAudioStream
+#endif
 		if (player->stream) // if audiostream has been opened, free it as well
-			free(player->stream);
+			SDL_DestroyAudioStream(player->stream);
 #endif
 		free(player);
 	}
diff --git a/SheepShaver/src/Unix/configure.ac b/SheepShaver/src/Unix/configure.ac
index 9a294f21..512ff56e 100755
--- a/SheepShaver/src/Unix/configure.ac
+++ b/SheepShaver/src/Unix/configure.ac
@@ -222,7 +222,7 @@ if [[ "x$WANT_SDL" = "xyes" ]]; then
     if [[ "x$TEMP_WANT_SDL_VERSION_MAJOR" = "x3" ]]; then
       PKG_CHECK_MODULES([sdl3], [sdl3 >= 3.0], [
         CXXFLAGS="$CXXFLAGS $sdl3_CFLAGS"
-        CXXFLAGS+=`echo $sdl3_CFLAGS | sed -e 's/\(-I.*include\)/\1\/SDL3/'`
+        CXXFLAGS+=`echo " $sdl3_CFLAGS" | sed -e 's/\(-I.*include\)/\1\/SDL3/'`
         LIBS="$LIBS $sdl3_LIBS"
         WANT_SDL_VERSION_MAJOR=3
       ], [
diff --git a/SheepShaver/src/Windows/configure.ac b/SheepShaver/src/Windows/configure.ac
index c572d44c..b6ded6a1 100644
--- a/SheepShaver/src/Windows/configure.ac
+++ b/SheepShaver/src/Windows/configure.ac
@@ -278,6 +278,7 @@ CPUSRCS="$CPUSRCS ../dummy/prefs_dummy.cpp"
 dnl We really want SDL for now
 if [[ "x$WANT_SDL_VERSION_MAJOR" = "x3" ]]; then
   SDL_CFLAGS=`pkg-config sdl3 --cflags`
+  SDL_CFLAGS+=`echo " $SDL_CFLAGS" | sed -e 's/\(-I.*include\)/\1\/SDL3/'`
   SDL_LIBS=`pkg-config sdl3 --libs | sed -e 's/-lSDL3/-lSDL3.dll/'`
 else
   SDL_CFLAGS=`sdl2-config --cflags`