diff --git a/sc2/src/sc2code/libs/sound/decoders/mikmod/mikmod.h b/sc2/src/sc2code/libs/sound/decoders/mikmod/mikmod.h
index dc259d972..a62d315a6 100644
--- a/sc2/src/sc2code/libs/sound/decoders/mikmod/mikmod.h
+++ b/sc2/src/sc2code/libs/sound/decoders/mikmod/mikmod.h
@@ -85,7 +85,7 @@ typedef char CHAR;
 
 /*@DOES_NOT_HAVE_SIGNED@*/
 
-#if defined(__alpha)
+#if defined(__arch64__) || defined(__alpha) || defined(__x86_64)
 /* 64 bit architectures */
 
 typedef signed char     SBYTE;      /* 1 byte, signed */
diff --git a/sc2/src/sc2code/libs/sound/decoders/mikmod/mikmod_internals.h b/sc2/src/sc2code/libs/sound/decoders/mikmod/mikmod_internals.h
index 5caf31c23..2fc648ca9 100644
--- a/sc2/src/sc2code/libs/sound/decoders/mikmod/mikmod_internals.h
+++ b/sc2/src/sc2code/libs/sound/decoders/mikmod/mikmod_internals.h
@@ -71,7 +71,7 @@ extern "C" {
 /*========== More type definitions */
 
 /* SLONGLONG: 64bit, signed */
-#if defined(__alpha)
+#if defined(__arch64__) || defined(__alpha) || defined(__x86_64)
 typedef long		SLONGLONG;
 #define NATIVE_64BIT_INT
 #elif defined(__WATCOMC__)