diff --git a/libavformat/mxfenc.c b/libavformat/mxfenc.c
index 45c2ff6297..928f3e1531 100644
--- a/libavformat/mxfenc.c
+++ b/libavformat/mxfenc.c
@@ -754,7 +754,7 @@ static void mxf_write_generic_desc(AVFormatContext *s, AVStream *st, const UID k
     ByteIOContext *pb = s->pb;
 
     put_buffer(pb, key, 16);
-    klv_encode_ber_length(pb, size+20+8+12+20);
+    klv_encode_ber4_length(pb, size+20+8+12+20);
 
     mxf_write_local_tag(pb, 16, 0x3C0A);
     mxf_write_uuid(pb, SubDescriptor, st->index);
diff --git a/tests/lavf.regression.ref b/tests/lavf.regression.ref
index 04121aceb1..4645c643ca 100644
--- a/tests/lavf.regression.ref
+++ b/tests/lavf.regression.ref
@@ -9,10 +9,10 @@ bc5e914594523f7c48f9e044c9a9c0b6 *./tests/data/b-lavf.avi
 bfdec98337e6a9d89dc648d1e65a41db *./tests/data/b-lavf.mpg
 378880 ./tests/data/b-lavf.mpg
 ./tests/data/b-lavf.mpg CRC=0xaf760568
-4c2cd0f62014a7c6571d8dbdf4248965 *./tests/data/b-lavf.mxf
+dfae2e9e7572c000bec1edb8ea3e6cf3 *./tests/data/b-lavf.mxf
 535097 ./tests/data/b-lavf.mxf
 ./tests/data/b-lavf.mxf CRC=0xd7ff387d
-4463959da5ebd7536a579a628c4f6412 *./tests/data/b-lavf.mxf_d10
+0cf22217d46b55c4fd178890305f9025 *./tests/data/b-lavf.mxf_d10
 5330989 ./tests/data/b-lavf.mxf_d10
 ./tests/data/b-lavf.mxf_d10 CRC=0xd241c8b6
 2e9bd99fbb121ae4887109e3a4169acd *./tests/data/b-lavf.ts