diff --git a/libavcodec/sgienc.c b/libavcodec/sgienc.c
index b88f6c3843..e7aa394069 100644
--- a/libavcodec/sgienc.c
+++ b/libavcodec/sgienc.c
@@ -171,8 +171,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
                 }
 
                 buf += length;
-                bytestream_put_byte(&buf, 0);
-                bytestream_put_be32(&lengthtab, length + 1);
+                bytestream_put_be32(&lengthtab, length);
                 in_buf -= p->linesize[0];
             }
         }
diff --git a/tests/ref/lavf/sgi b/tests/ref/lavf/sgi
index b0cd303735..703b83cf66 100644
--- a/tests/ref/lavf/sgi
+++ b/tests/ref/lavf/sgi
@@ -1,3 +1,3 @@
-7054acafd275e51cec28d4518e213081 *./tests/data/images/sgi/02.sgi
+d446e540a7c18da5fd3cc0e9942cd46f *./tests/data/images/sgi/02.sgi
 ./tests/data/images/sgi/%02d.sgi CRC=0x28c7369b
-308151 ./tests/data/images/sgi/02.sgi
+307287 ./tests/data/images/sgi/02.sgi
diff --git a/tests/ref/seek/lavf-sgi b/tests/ref/seek/lavf-sgi
index b2f605ad94..04c7b2b1a4 100644
--- a/tests/ref/seek/lavf-sgi
+++ b/tests/ref/seek/lavf-sgi
@@ -1,4 +1,4 @@
-ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:     -1 size:308336
+ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:     -1 size:307472
 ret:-EINVAL    st:-1 flags:0  ts:-1.000000
 ret:-EINVAL    st:-1 flags:1  ts: 1.894167
 ret:-EINVAL    st: 0 flags:0  ts: 0.800000