diff --git a/src/deutex.h b/src/deutex.h
index 0a26df5..7af321c 100644
--- a/src/deutex.h
+++ b/src/deutex.h
@@ -31,7 +31,7 @@ Place, Suite 330, Boston, MA 02111-1307, USA.
 #define DeuSF   for DOS .EXE  Unix Linux OS/2
 *********************************************/
 
-#if defined (__alpha)        /*__ALPHA__ for Alpha processor?*/
+#if defined (__alpha) || defined (__x86_64__)        /*__ALPHA__ for Alpha processor?*/
 /*long = int64 on a 64bit processor*/
 typedef char           Int8;
 typedef short          Int16;
