diff --git a/libavformat/av1.c b/libavformat/av1.c
index 79065d0c9f..b6eaf50627 100644
--- a/libavformat/av1.c
+++ b/libavformat/av1.c
@@ -395,7 +395,8 @@ int ff_av1_parse_seq_header(AV1SequenceParameters *seq, const uint8_t *buf, int
     return is_av1c ? 0 : AVERROR_INVALIDDATA;
 }
 
-int ff_isom_write_av1c(AVIOContext *pb, const uint8_t *buf, int size)
+int ff_isom_write_av1c(AVIOContext *pb, const uint8_t *buf, int size,
+                       int write_seq_header)
 {
     AVIOContext *meta_pb;
     AV1SequenceParameters seq_params;
@@ -485,7 +486,9 @@ int ff_isom_write_av1c(AVIOContext *pb, const uint8_t *buf, int size)
     flush_put_bits(&pbc);
 
     avio_write(pb, header, sizeof(header));
-    avio_write(pb, seq, seq_size);
+    if (write_seq_header) {
+        avio_write(pb, seq, seq_size);
+    }
 
     meta_size = avio_get_dyn_buf(meta_pb, &meta);
     if (meta_size)
diff --git a/libavformat/av1.h b/libavformat/av1.h
index f57dabe986..a393fbb78f 100644
--- a/libavformat/av1.h
+++ b/libavformat/av1.h
@@ -96,9 +96,11 @@ int ff_av1_parse_seq_header(AV1SequenceParameters *seq, const uint8_t *buf, int
  * @param pb pointer to the AVIOContext where the av1C box shall be written
  * @param buf input data buffer
  * @param size size in bytes of the input data buffer
+ * @param write_seq_header If 1, Sequence Header OBU will be written inside the
+ *           av1C box. Otherwise, Sequence Header OBU will be omitted.
  *
  * @return >= 0 in case of success, a negative AVERROR code in case of failure
  */
-int ff_isom_write_av1c(AVIOContext *pb, const uint8_t *buf, int size);
+int ff_isom_write_av1c(AVIOContext *pb, const uint8_t *buf, int size, int write_seq_header);
 
 #endif /* AVFORMAT_AV1_H */
diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
index c30584949a..482b5812e5 100644
--- a/libavformat/matroskaenc.c
+++ b/libavformat/matroskaenc.c
@@ -1089,7 +1089,7 @@ static int mkv_write_native_codecprivate(AVFormatContext *s, AVIOContext *pb,
     case AV_CODEC_ID_AV1:
         if (par->extradata_size)
             return ff_isom_write_av1c(dyn_cp, par->extradata,
-                                      par->extradata_size);
+                                      par->extradata_size, 1);
         else
             put_ebml_void(pb, 4 + 3);
         break;
@@ -2665,7 +2665,7 @@ static int mkv_check_new_extra_data(AVFormatContext *s, const AVPacket *pkt)
             ret = avio_open_dyn_buf(&dyn_cp);
             if (ret < 0)
                 return ret;
-            ff_isom_write_av1c(dyn_cp, side_data, side_data_size);
+            ff_isom_write_av1c(dyn_cp, side_data, side_data_size, 1);
             codecpriv_size = avio_get_dyn_buf(dyn_cp, &codecpriv);
             if ((ret = dyn_cp->error) < 0 ||
                 !codecpriv_size && (ret = AVERROR_INVALIDDATA)) {
diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index c720fd742d..8cb352a0f9 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -1337,7 +1337,7 @@ static int mov_write_av1c_tag(AVIOContext *pb, MOVTrack *track)
 
     avio_wb32(pb, 0);
     ffio_wfourcc(pb, "av1C");
-    ff_isom_write_av1c(pb, track->vos_data, track->vos_len);
+    ff_isom_write_av1c(pb, track->vos_data, track->vos_len, 1);
     return update_size(pb, pos);
 }