diff --git a/Win32/Include/bittypes.h b/Win32/Include/bittypes.h
index c84077a..558a0b5 100644
--- a/Win32/Include/bittypes.h
+++ b/Win32/Include/bittypes.h
@@ -86,8 +86,10 @@ typedef signed short int32_t;
 #ifndef HAVE_U_INT64_T
 #if SIZEOF_LONG_LONG == 8
 typedef unsigned long long u_int64_t;
+typedef long long int64_t;
 #elif defined(_MSC_EXTENSIONS)
 typedef unsigned _int64 u_int64_t;
+typedef _int64 int64_t;
 #elif SIZEOF_INT == 8
 typedef unsigned int u_int64_t;
 #elif SIZEOF_LONG == 8