diff --git a/rtl/inc/heaptrc.pp b/rtl/inc/heaptrc.pp
index 920f448293..0f6eaaab2a 100644
--- a/rtl/inc/heaptrc.pp
+++ b/rtl/inc/heaptrc.pp
@@ -1679,7 +1679,7 @@ begin
     Add some way to specify heaptrc options? }
   GetEnv:=nil;
 end;
-{$elseif defined(msdos)}
+{$elseif defined(msdos) or defined(msxdos)}
    type
      PFarChar=^Char;far;
      PPFarChar=^PFarChar;