diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index c4ef964cc1..0111777cd8 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -1145,7 +1145,8 @@ static int mov_write_ilst_tag(ByteIOContext *pb, MOVContext* mov,
     mov_write_string_tag(pb, "\251wrt", s->author        , 1);
     mov_write_string_tag(pb, "\251alb", s->album         , 1);
     mov_write_day_tag(pb, s->year ,1);
-    mov_write_string_tag(pb, "\251too", LIBAVFORMAT_IDENT, 1);
+    if(mov->tracks[0].enc && !(mov->tracks[0].enc->flags & CODEC_FLAG_BITEXACT))
+        mov_write_string_tag(pb, "\251too", LIBAVFORMAT_IDENT, 1);
     mov_write_string_tag(pb, "\251cmt", s->comment       , 1);
     mov_write_string_tag(pb, "\251gen", s->genre         , 1);
     mov_write_trkn_tag(pb, mov, s);