diff --git a/Xmd.h b/Xmd.h
index fe8d02b..80fbe7c 100644
--- a/Xmd.h
+++ b/Xmd.h
@@ -139,7 +139,7 @@ typedef long INT32;
 typedef short INT16;
 #endif
 
-#if defined(__STDC__) || defined(sgi) || defined(AIXV3)
+#if defined(__STDC__) || defined(sgi) || defined(_AIX)
 typedef signed char    INT8;
 #else
 typedef char           INT8;
@@ -151,6 +151,9 @@ typedef unsigned int CARD32;
 #else
 typedef unsigned long CARD32;
 #endif
+#if !defined(WORD64) && !defined(LONG64)
+typedef unsigned long long CARD64;
+#endif
 typedef unsigned short CARD16;
 typedef unsigned char  CARD8;