diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
index 79ea35373e3be3cca33ddc4a45ccd2fc34a4e768..6b5d3ac26ad3a468cee5997bfb07091f058eeef5 100644
--- a/libavformat/matroskaenc.c
+++ b/libavformat/matroskaenc.c
@@ -778,7 +778,7 @@ static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
         ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt->size));
         duration = pkt->convergence_duration;
         mkv_write_block(s, MATROSKA_ID_BLOCK, pkt, 0);
-        put_ebml_uint(pb, MATROSKA_ID_DURATION, duration);
+        put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
         end_ebml_master(pb, blockgroup);
     }