diff --git a/libavformat/internal.h b/libavformat/internal.h
index d85b9a3d9b..8631694d00 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -98,6 +98,9 @@ struct AVFormatInternal {
      * for short periods that are guaranteed not to overlap
      * with calls to av_read_frame() (or ff_read_packet())
      * or with each other.
+     * It may be used by demuxers as a replacement for
+     * stack packets (unless they call one of the aforementioned
+     * functions with their own AVFormatContext).
      * Every user has to ensure that this packet is blank
      * after using it.
      */
diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 9acfdf5b32..1dc188c946 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -381,6 +381,8 @@ typedef struct MatroskaDemuxContext {
     /* byte position of the segment inside the stream */
     int64_t segment_start;
 
+    /* This packet coincides with AVFormatInternal.parse_pkt
+     * and is not owned by us. */
     AVPacket *pkt;
 
     /* the packet queue */
@@ -2945,9 +2947,7 @@ static int matroska_read_header(AVFormatContext *s)
     }
     ebml_free(ebml_syntax, &ebml);
 
-    matroska->pkt = av_packet_alloc();
-    if (!matroska->pkt)
-        return AVERROR(ENOMEM);
+    matroska->pkt = s->internal->parse_pkt;
 
     /* The next thing is a segment. */
     pos = avio_tell(matroska->ctx->pb);
@@ -3528,7 +3528,6 @@ static int matroska_parse_frame(MatroskaDemuxContext *matroska,
     if (!pkt_size && !additional_size)
         goto no_output;
 
-    av_packet_unref(pkt);
     if (!buf)
         pkt->buf = av_buffer_create(pkt_data, pkt_size + AV_INPUT_BUFFER_PADDING_SIZE,
                                     NULL, NULL, 0);
@@ -3902,7 +3901,6 @@ static int matroska_read_close(AVFormatContext *s)
     int n;
 
     matroska_clear_queue(matroska);
-    av_packet_free(&matroska->pkt);
 
     for (n = 0; n < matroska->tracks.nb_elem; n++)
         if (tracks[n].type == MATROSKA_TRACK_TYPE_AUDIO)