diff -ur SDL_mixer-1.2.5-old/mikmod/mikmod.h SDL_mixer-1.2.5/mikmod/mikmod.h
--- SDL_mixer-1.2.5-old/mikmod/mikmod.h	2004-05-27 11:16:29.571640904 -0500
+++ SDL_mixer-1.2.5/mikmod/mikmod.h	2004-05-27 11:17:07.233915368 -0500
@@ -85,7 +85,7 @@
 
 /*@DOES_NOT_HAVE_SIGNED@*/
 
-#if defined(__alpha)
+#if defined(__alpha) || defined(__x86_64)
 /* 64 bit architectures */
 
 typedef signed char     SBYTE;      /* 1 byte, signed */
diff -ur SDL_mixer-1.2.5-old/mikmod/mikmod_internals.h SDL_mixer-1.2.5/mikmod/mikmod_internals.h
--- SDL_mixer-1.2.5-old/mikmod/mikmod_internals.h	2004-05-27 11:16:29.571640904 -0500
+++ SDL_mixer-1.2.5/mikmod/mikmod_internals.h	2004-05-27 11:17:31.622207784 -0500
@@ -69,7 +69,7 @@
 /*========== More type definitions */
 
 /* SLONGLONG: 64bit, signed */
-#if defined(__alpha)
+#if defined(__alpha) || defined(__x86_64)
 typedef long		SLONGLONG;
 #define NATIVE_64BIT_INT
 #elif defined(__WATCOMC__)