diff --git a/libavformat/isom.c b/libavformat/isom.c
index cf27f58082..6d019881e5 100644
--- a/libavformat/isom.c
+++ b/libavformat/isom.c
@@ -61,7 +61,6 @@ const AVCodecTag ff_mp4_obj_type[] = {
     { AV_CODEC_ID_DTS         , 0xA9 }, /* mp4ra.org */
     { AV_CODEC_ID_OPUS        , 0xAD }, /* mp4ra.org */
     { AV_CODEC_ID_VP9         , 0xB1 }, /* mp4ra.org */
-    { AV_CODEC_ID_FLAC        , 0xC1 }, /* nonstandard, update when there is a standard value */
     { AV_CODEC_ID_TSCC2       , 0xD0 }, /* nonstandard, camtasia uses it */
     { AV_CODEC_ID_EVRC        , 0xD1 }, /* nonstandard, pvAuthor uses it */
     { AV_CODEC_ID_VORBIS      , 0xDD }, /* nonstandard, gpac uses it */
diff --git a/libavformat/isom_tags.c b/libavformat/isom_tags.c
index c5fd7987f6..362cb77e8f 100644
--- a/libavformat/isom_tags.c
+++ b/libavformat/isom_tags.c
@@ -332,7 +332,7 @@ const AVCodecTag ff_codec_movaudio_tags[] = {
     { AV_CODEC_ID_SPEEX,           MKTAG('S', 'P', 'X', 'N') }, /* ZygoAudio (quality 10 mode) */
     { AV_CODEC_ID_EVRC,            MKTAG('s', 'e', 'v', 'c') }, /* 3GPP2 */
     { AV_CODEC_ID_SMV,             MKTAG('s', 's', 'm', 'v') }, /* 3GPP2 */
-    { AV_CODEC_ID_FLAC,            MKTAG('f', 'L', 'a', 'C') }, /* nonstandard */
+    { AV_CODEC_ID_FLAC,            MKTAG('f', 'L', 'a', 'C') },
     { AV_CODEC_ID_TRUEHD,          MKTAG('m', 'l', 'p', 'a') }, /* mp4ra.org */
     { AV_CODEC_ID_OPUS,            MKTAG('O', 'p', 'u', 's') }, /* mp4ra.org */
     { AV_CODEC_ID_MPEGH_3D_AUDIO,  MKTAG('m', 'h', 'm', '1') }, /* MPEG-H 3D Audio bitstream */
diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 5608afde42..c8b2e141cb 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -7160,7 +7160,7 @@ static int mov_init(AVFormatContext *s)
                     av_log(s, AV_LOG_ERROR, "%s only supported in MP4.\n", avcodec_get_name(track->par->codec_id));
                     return AVERROR(EINVAL);
                 }
-                if (track->par->codec_id != AV_CODEC_ID_OPUS &&
+                if (track->par->codec_id == AV_CODEC_ID_TRUEHD &&
                     s->strict_std_compliance > FF_COMPLIANCE_EXPERIMENTAL) {
                     av_log(s, AV_LOG_ERROR,
                            "%s in MP4 support is experimental, add "