diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index d79607b3b86bc9258c3f2716a95dcbc15548d081..80a44cf18665eda0e426954a59d7dfba75068e61 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -2748,8 +2748,6 @@ static int mov_write_ftyp_tag(AVIOContext *pb, AVFormatContext *s)
         ffio_wfourcc(pb, "qt  ");
     else if (mov->mode == MODE_ISM) {
         ffio_wfourcc(pb, "piff");
-        if (!(mov->flags & FF_MOV_FLAG_DEFAULT_BASE_MOOF))
-            ffio_wfourcc(pb, "iso2");
     } else if (!(mov->flags & FF_MOV_FLAG_DEFAULT_BASE_MOOF)) {
         ffio_wfourcc(pb, "isom");
         ffio_wfourcc(pb, "iso2");