diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
index 375f728e618542d8e20cce72c205bb1828dd9e61..bcded7c0609f4ddc0e77ba21309e18582ec3187e 100644
--- a/libavformat/matroskaenc.c
+++ b/libavformat/matroskaenc.c
@@ -902,6 +902,9 @@ static int mkv_write_header(AVFormatContext *s)
     if (!strcmp(s->oformat->name, "webm")) mkv->mode = MODE_WEBM;
     else                                   mkv->mode = MODE_MATROSKAv2;
 
+    if (s->avoid_negative_ts < 0)
+        s->avoid_negative_ts = 1;
+
     mkv->tracks = av_mallocz(s->nb_streams * sizeof(*mkv->tracks));
     if (!mkv->tracks)
         return AVERROR(ENOMEM);
diff --git a/tests/ref/lavf/mkv b/tests/ref/lavf/mkv
index 8820300100a91ad158d6194e6b9283a0384c1290..d92aaa8c8143f9c9b50497aaa1f8587d2485029e 100644
--- a/tests/ref/lavf/mkv
+++ b/tests/ref/lavf/mkv
@@ -1,3 +1,3 @@
-796a3bbf2410e55e186367037bda6bb5 *./tests/data/lavf/lavf.mkv
+84dcb326fe85aeeb5768beb44372f248 *./tests/data/lavf/lavf.mkv
 320297 ./tests/data/lavf/lavf.mkv
-./tests/data/lavf/lavf.mkv CRC=0x7065846b
+./tests/data/lavf/lavf.mkv CRC=0x4780846b
diff --git a/tests/ref/seek/lavf_mkv b/tests/ref/seek/lavf_mkv
index ece15a1d751f27ac72284d3a525fdae8d4cf940f..681462ccccb4337b120309f56ff56a89f56597e1 100644
--- a/tests/ref/seek/lavf_mkv
+++ b/tests/ref/seek/lavf_mkv
@@ -1,48 +1,48 @@
-ret: 0         st: 1 flags:1 dts:-0.011000 pts:-0.011000 pos:    555 size:   208
-ret: 0         st:-1 flags:0  ts:-1.000000
 ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    555 size:   208
+ret: 0         st:-1 flags:0  ts:-1.000000
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:    771 size: 27837
 ret: 0         st:-1 flags:1  ts: 1.894167
-ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos: 292185 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292185 size: 27834
 ret: 0         st: 0 flags:0  ts: 0.788000
-ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos: 292185 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292185 size: 27834
 ret: 0         st: 0 flags:1  ts:-0.317000
-ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    555 size:   208
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:    771 size: 27837
 ret:-1         st: 1 flags:0  ts: 2.577000
 ret: 0         st: 1 flags:1  ts: 1.471000
-ret: 0         st: 1 flags:1 dts: 0.982000 pts: 0.982000 pos: 320026 size:   209
+ret: 0         st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320026 size:   209
 ret: 0         st:-1 flags:0  ts: 0.365002
-ret: 0         st: 0 flags:1 dts: 0.480000 pts: 0.480000 pos: 146738 size: 27925
+ret: 0         st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146738 size: 27925
 ret: 0         st:-1 flags:1  ts:-0.740831
-ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    555 size:   208
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:    771 size: 27837
 ret:-1         st: 0 flags:0  ts: 2.153000
 ret: 0         st: 0 flags:1  ts: 1.048000
-ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos: 292185 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292185 size: 27834
 ret: 0         st: 1 flags:0  ts:-0.058000
-ret: 0         st: 1 flags:1 dts: 0.015000 pts: 0.015000 pos:    555 size:   208
+ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    555 size:   208
 ret: 0         st: 1 flags:1  ts: 2.836000
-ret: 0         st: 1 flags:1 dts: 0.982000 pts: 0.982000 pos: 320026 size:   209
+ret: 0         st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320026 size:   209
 ret:-1         st:-1 flags:0  ts: 1.730004
 ret: 0         st:-1 flags:1  ts: 0.624171
-ret: 0         st: 0 flags:1 dts: 0.480000 pts: 0.480000 pos: 146738 size: 27925
+ret: 0         st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146738 size: 27925
 ret: 0         st: 0 flags:0  ts:-0.482000
-ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    555 size:   208
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:    771 size: 27837
 ret: 0         st: 0 flags:1  ts: 2.413000
-ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos: 292185 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292185 size: 27834
 ret:-1         st: 1 flags:0  ts: 1.307000
 ret: 0         st: 1 flags:1  ts: 0.201000
-ret: 0         st: 1 flags:1 dts: 0.015000 pts: 0.015000 pos:    555 size:   208
-ret: 0         st:-1 flags:0  ts:-0.904994
 ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    555 size:   208
+ret: 0         st:-1 flags:0  ts:-0.904994
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:    771 size: 27837
 ret: 0         st:-1 flags:1  ts: 1.989173
-ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos: 292185 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292185 size: 27834
 ret: 0         st: 0 flags:0  ts: 0.883000
-ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos: 292185 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292185 size: 27834
 ret: 0         st: 0 flags:1  ts:-0.222000
-ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    555 size:   208
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:    771 size: 27837
 ret:-1         st: 1 flags:0  ts: 2.672000
 ret: 0         st: 1 flags:1  ts: 1.566000
-ret: 0         st: 1 flags:1 dts: 0.982000 pts: 0.982000 pos: 320026 size:   209
+ret: 0         st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320026 size:   209
 ret: 0         st:-1 flags:0  ts: 0.460008
-ret: 0         st: 0 flags:1 dts: 0.480000 pts: 0.480000 pos: 146738 size: 27925
+ret: 0         st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146738 size: 27925
 ret: 0         st:-1 flags:1  ts:-0.645825
-ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    555 size:   208
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:    771 size: 27837