diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
index 1bbf6c6..da45f7c 100644
--- a/libavformat/matroskaenc.c
+++ b/libavformat/matroskaenc.c
@@ -391,9 +391,9 @@ static mkv_seekhead *mkv_start_seekhead(AVIOContext *pb, int64_t segment_offset,
     if (numelements > 0) {
         new_seekhead->filepos = avio_tell(pb);
         // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
-        // and size, and 3 bytes to guarantee that an EBML void element
-        // will fit afterwards
-        new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
+        // and size, 6 bytes for a CRC32 element, and 3 bytes to guarantee
+        // that an EBML void element will fit afterwards
+        new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 19;
         new_seekhead->max_entries   = numelements;
         put_ebml_void(pb, new_seekhead->reserved_size);
     }
@@ -430,6 +430,7 @@ static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid
  */
 static int64_t mkv_write_seekhead(AVIOContext *pb, MatroskaMuxContext *mkv)
 {
+    AVIOContext *dyn_cp;
     mkv_seekhead *seekhead = mkv->main_seekhead;
     ebml_master metaseek, seekentry;
     int64_t currentpos;
@@ -444,20 +445,25 @@ static int64_t mkv_write_seekhead(AVIOContext *pb, MatroskaMuxContext *mkv)
         }
     }
 
-    metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
+    if (start_ebml_master_crc32(pb, &dyn_cp, &metaseek, MATROSKA_ID_SEEKHEAD,
+                                seekhead->reserved_size) < 0) {
+        currentpos = -1;
+        goto fail;
+    }
+
     for (i = 0; i < seekhead->num_entries; i++) {
         mkv_seekhead_entry *entry = &seekhead->entries[i];
 
-        seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
+        seekentry = start_ebml_master(dyn_cp, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
 
-        put_ebml_id(pb, MATROSKA_ID_SEEKID);
-        put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
-        put_ebml_id(pb, entry->elementid);
+        put_ebml_id(dyn_cp, MATROSKA_ID_SEEKID);
+        put_ebml_num(dyn_cp, ebml_id_size(entry->elementid), 0);
+        put_ebml_id(dyn_cp, entry->elementid);
 
-        put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
-        end_ebml_master(pb, seekentry);
+        put_ebml_uint(dyn_cp, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
+        end_ebml_master(dyn_cp, seekentry);
     }
-    end_ebml_master(pb, metaseek);
+    end_ebml_master_crc32(pb, &dyn_cp, mkv, metaseek);
 
     if (seekhead->reserved_size > 0) {
         uint64_t remaining = seekhead->filepos + seekhead->reserved_size - avio_tell(pb);
diff --git a/tests/fate/matroska.mak b/tests/fate/matroska.mak
index 36cc779..7de9a59 100644
--- a/tests/fate/matroska.mak
+++ b/tests/fate/matroska.mak
@@ -4,6 +4,6 @@
 FATE_MATROSKA-$(call DEMMUX, MATROSKA, MATROSKA) += fate-matroska-remux
 fate-matroska-remux: CMD = md5 -i $(TARGET_SAMPLES)/vp9-test-vectors/vp90-2-2pass-akiyo.webm -color_trc 4 -c:v copy -fflags +bitexact -strict -2 -f matroska
 fate-matroska-remux: CMP = oneline
-fate-matroska-remux: REF = 1040692ffdfee2428954af79a7d5d155
+fate-matroska-remux: REF = d1a5fc15908ba10ca3efa282059ca79f
 
 FATE_SAMPLES_AVCONV += $(FATE_MATROSKA-yes)
diff --git a/tests/fate/wavpack.mak b/tests/fate/wavpack.mak
index 240f5ea..32ae3f6 100644
--- a/tests/fate/wavpack.mak
+++ b/tests/fate/wavpack.mak
@@ -91,12 +91,12 @@ fate-wavpack-matroskamode: CMD = md5 -i $(TARGET_SAMPLES)/wavpack/special/matros
 FATE_WAVPACK-$(call DEMMUX, WV, MATROSKA) += fate-wavpack-matroska_mux-mono
 fate-wavpack-matroska_mux-mono: CMD = md5 -i $(TARGET_SAMPLES)/wavpack/num_channels/mono_16bit_int.wv -c copy -fflags +bitexact -f matroska
 fate-wavpack-matroska_mux-mono: CMP = oneline
-fate-wavpack-matroska_mux-mono: REF = a2987e2e51e01a35e47e7da13eb47a35
+fate-wavpack-matroska_mux-mono: REF = 11773e2a518edc788475f3880d849230
 
 FATE_WAVPACK-$(call DEMMUX, WV, MATROSKA) += fate-wavpack-matroska_mux-61
 fate-wavpack-matroska_mux-61: CMD = md5 -i $(TARGET_SAMPLES)/wavpack/num_channels/eva_2.22_6.1_16bit-partial.wv -c copy -fflags +bitexact -f matroska
 fate-wavpack-matroska_mux-61: CMP = oneline
-fate-wavpack-matroska_mux-61: REF = ffba4ddea1ba71f7a5901d9ed1a267be
+fate-wavpack-matroska_mux-61: REF = 9641abdf596c10c2e21bd9b026d4bade
 
 FATE_SAMPLES_AVCONV += $(FATE_WAVPACK-yes)
 fate-wavpack: $(FATE_WAVPACK-yes)
diff --git a/tests/ref/fate/binsub-mksenc b/tests/ref/fate/binsub-mksenc
index c473497..f247d9d 100644
--- a/tests/ref/fate/binsub-mksenc
+++ b/tests/ref/fate/binsub-mksenc
@@ -1 +1 @@
-2dad5f63688ec613a04e94c8d4d167db
+f80f42e646fce972e73aa6d99dcfa470
diff --git a/tests/ref/fate/rgb24-mkv b/tests/ref/fate/rgb24-mkv
index d624488..6bcffa1 100644
--- a/tests/ref/fate/rgb24-mkv
+++ b/tests/ref/fate/rgb24-mkv
@@ -1,5 +1,5 @@
-ec5c058001761fd1d885839ad79f1af6 *tests/data/fate/rgb24-mkv.matroska
-58334 tests/data/fate/rgb24-mkv.matroska
+c368e77c46109ac20e279ff83f9649b3 *tests/data/fate/rgb24-mkv.matroska
+58340 tests/data/fate/rgb24-mkv.matroska
 #tb 0: 1/10
 #media_type 0: video
 #codec_id 0: rawvideo
diff --git a/tests/ref/lavf/mka b/tests/ref/lavf/mka
index bbdff15..3852d28 100644
--- a/tests/ref/lavf/mka
+++ b/tests/ref/lavf/mka
@@ -1,3 +1,3 @@
-56dab37c9f48bf0f9f16cfed8f1f6c17 *./tests/data/lavf/lavf.mka
-43660 ./tests/data/lavf/lavf.mka
+57d2f97a7c4d13c97212cb0f76f72e10 *./tests/data/lavf/lavf.mka
+43666 ./tests/data/lavf/lavf.mka
 ./tests/data/lavf/lavf.mka CRC=0x3a1da17e
diff --git a/tests/ref/lavf/mkv b/tests/ref/lavf/mkv
index 91c0ac4..9c9394f 100644
--- a/tests/ref/lavf/mkv
+++ b/tests/ref/lavf/mkv
@@ -1,6 +1,6 @@
-6d72c4935937347cc501981aa303996a *./tests/data/lavf/lavf.mkv
-472914 ./tests/data/lavf/lavf.mkv
+161e0ed817bd65194fd4001c0d5380f0 *./tests/data/lavf/lavf.mkv
+472920 ./tests/data/lavf/lavf.mkv
 ./tests/data/lavf/lavf.mkv CRC=0xec6c3c68
-107655a82446e6a44b2a26e0a908b901 *./tests/data/lavf/lavf.mkv
-320590 ./tests/data/lavf/lavf.mkv
+7afba147b92da5115095fa52e214cfee *./tests/data/lavf/lavf.mkv
+320596 ./tests/data/lavf/lavf.mkv
 ./tests/data/lavf/lavf.mkv CRC=0xec6c3c68
diff --git a/tests/ref/seek/lavf-mkv b/tests/ref/seek/lavf-mkv
index 12d6983..0662f2f 100644
--- a/tests/ref/seek/lavf-mkv
+++ b/tests/ref/seek/lavf-mkv
@@ -1,48 +1,48 @@
-ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    806 size:   208
+ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    812 size:   208
 ret: 0         st:-1 flags:0  ts:-1.000000
-ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1022 size: 27837
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1028 size: 27837
 ret: 0         st:-1 flags:1  ts: 1.894167
-ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292448 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292454 size: 27834
 ret: 0         st: 0 flags:0  ts: 0.788000
-ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292448 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292454 size: 27834
 ret: 0         st: 0 flags:1  ts:-0.317000
-ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1022 size: 27837
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1028 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: 0.993000 pts: 0.993000 pos: 320289 size:   209
+ret: 0         st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320295 size:   209
 ret: 0         st:-1 flags:0  ts: 0.365002
-ret: 0         st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146995 size: 27925
+ret: 0         st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 147001 size: 27925
 ret: 0         st:-1 flags:1  ts:-0.740831
-ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1022 size: 27837
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1028 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: 0.971000 pts: 0.971000 pos: 292448 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292454 size: 27834
 ret: 0         st: 1 flags:0  ts:-0.058000
-ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    806 size:   208
+ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    812 size:   208
 ret: 0         st: 1 flags:1  ts: 2.836000
-ret: 0         st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320289 size:   209
+ret: 0         st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320295 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: 0.491000 pts: 0.491000 pos: 146995 size: 27925
+ret: 0         st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 147001 size: 27925
 ret: 0         st: 0 flags:0  ts:-0.482000
-ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1022 size: 27837
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1028 size: 27837
 ret: 0         st: 0 flags:1  ts: 2.413000
-ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292448 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292454 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: 0.000000 pts: 0.000000 pos:    806 size:   208
+ret: 0         st: 1 flags:1 dts: 0.000000 pts: 0.000000 pos:    812 size:   208
 ret: 0         st:-1 flags:0  ts:-0.904994
-ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1022 size: 27837
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1028 size: 27837
 ret: 0         st:-1 flags:1  ts: 1.989173
-ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292448 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292454 size: 27834
 ret: 0         st: 0 flags:0  ts: 0.883000
-ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292448 size: 27834
+ret: 0         st: 0 flags:1 dts: 0.971000 pts: 0.971000 pos: 292454 size: 27834
 ret: 0         st: 0 flags:1  ts:-0.222000
-ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1022 size: 27837
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1028 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: 0.993000 pts: 0.993000 pos: 320289 size:   209
+ret: 0         st: 1 flags:1 dts: 0.993000 pts: 0.993000 pos: 320295 size:   209
 ret: 0         st:-1 flags:0  ts: 0.460008
-ret: 0         st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 146995 size: 27925
+ret: 0         st: 0 flags:1 dts: 0.491000 pts: 0.491000 pos: 147001 size: 27925
 ret: 0         st:-1 flags:1  ts:-0.645825
-ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1022 size: 27837
+ret: 0         st: 0 flags:1 dts: 0.011000 pts: 0.011000 pos:   1028 size: 27837
