diff --git a/SDK/INC/NT/ntdef.h b/SDK/INC/NT/ntdef.h
index 97165c7..29f48e3 100644
--- a/SDK/INC/NT/ntdef.h
+++ b/SDK/INC/NT/ntdef.h
@@ -114,7 +114,8 @@ typedef unsigned long long ULONGLONG;
 typedef LONGLONG *PLONGLONG;
 typedef ULONGLONG *PULONGLONG;
 
-#define MAXLONGLONG  (0x7fffffffffffffff)
+#define MAXLONGLONG  0x7fffffffffffffff
+#define MAXULONGLONG 0xffffffffffffffff
 
 //
 // Logical/boolean value types.