diff -r 3acd16ea0180 -r d74fbf56f2f6 src/audio/SDL_audio.c
--- a/src/audio/SDL_audio.c	Sat Sep 11 18:00:41 2004 +0000
+++ b/src/audio/SDL_audio.c	Fri Sep 17 13:20:10 2004 +0000
@@ -399,7 +399,7 @@
 		return(-1);
 	}
 
-#if defined(macintosh) || defined(__riscos__)
+#if defined(macintosh) || (defined(__riscos__) && !defined(DISABLE_THREADS))
 	/* FIXME: Need to implement PPC interrupt asm for SDL_LockAudio() */
 #else
 #if defined(__MINT__) && !defined(ENABLE_THREADS)