diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 129de9065f..6e0e880fbc 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -1615,7 +1615,7 @@ static int matroska_read_header(AVFormatContext *s)
             avio_wl16(&b, track->audio.channels);
             avio_wl16(&b, track->audio.bitdepth);
             avio_wl32(&b, track->audio.out_samplerate);
-            avio_wl32(&b, matroska->ctx->duration * track->audio.out_samplerate);
+            avio_wl32(&b, av_rescale((matroska->duration * matroska->time_scale), track->audio.out_samplerate, AV_TIME_BASE * 1000));
         } else if (codec_id == CODEC_ID_RV10 || codec_id == CODEC_ID_RV20 ||
                    codec_id == CODEC_ID_RV30 || codec_id == CODEC_ID_RV40) {
             extradata_offset = 26;