diff --git a/libavcodec/cbs_av1_syntax_template.c b/libavcodec/cbs_av1_syntax_template.c
index f43c3a4de5..f3d84f3c05 100644
--- a/libavcodec/cbs_av1_syntax_template.c
+++ b/libavcodec/cbs_av1_syntax_template.c
@@ -186,10 +186,13 @@ static int FUNC(decoder_model_info)(CodedBitstreamContext *ctx, RWContext *rw,
 static int FUNC(sequence_header_obu)(CodedBitstreamContext *ctx, RWContext *rw,
                                      AV1RawSequenceHeader *current)
 {
+    CodedBitstreamAV1Context *priv = ctx->priv_data;
     int i, err;
 
     HEADER("Sequence Header");
 
+    priv->seen_frame_header = 0;
+
     fc(3, seq_profile, AV_PROFILE_AV1_MAIN,
                        AV_PROFILE_AV1_PROFESSIONAL);
     flag(still_picture);