--- a/include/SDL_config_macosx.h	Thu Apr 27 09:09:48 2006 +0000
+++ b/include/SDL_config_macosx.h	Fri Apr 28 16:55:41 2006 +0000
@@ -46,7 +46,12 @@
 #define HAVE_CALLOC	1
 #define HAVE_REALLOC	1
 #define HAVE_FREE	1
+
+/* If we specified an SDK or have a post-PowerPC chip, then alloca.h exists. */
+#if ( (MAC_OS_X_VERSION_MIN_REQUIRED >= 1030) || (!defined(__POWERPC__)) )
 #define HAVE_ALLOCA	1
+#endif
+
 #define HAVE_GETENV	1
 #define HAVE_PUTENV	1
 #define HAVE_UNSETENV	1