diff --git a/uutlCompression.pas b/uutlCompression.pas
index 00001d7..67253bc 100644
--- a/uutlCompression.pas
+++ b/uutlCompression.pas
@@ -1082,7 +1082,7 @@ begin
         if res < 0 then
           Exit;
         // setup writing to next part
-        inc(fStream.next_out, current_read);
+        fStream.next_out:= @Tbytearray(Buffer)[Result];
         dec(Count, current_read);
         fStream.avail_out:= Count;
         // re-read from this new block