build               | 8 ++++++--
 doc/INSTALL         | 7 +++++--
 internal/version.go | 2 +-
 makedist            | 1 -

diff --git a/build b/build
index 4372d1a259ad1c1ee9e6021792c39acc4fb1a0056f933bcd74106571490086b3..0c444255a756c3940fa8497338e4f36c413baa582336e68d442c92555894a698 100755
--- a/build
+++ b/build
@@ -1,9 +1,13 @@
 #!/bin/sh -e
 
-opus=opus-1.5.2
+opus=opus-1.6
+[ -e $opus.tar.gz ] || {
+    echo fetch https://downloads.xiph.org/releases/opus/opus-1.6.tar.gz >&2
+    exit 1
+}
 if ! [ -d local/lib ] ; then
     rm -fr local $opus
-    tar xf $opus.tar
+    tar xf $opus.tar*
     cd $opus
     ./configure --prefix=$(realpath ..)/local \
         --enable-deep-plc \
diff --git a/doc/INSTALL b/doc/INSTALL
index 325f35441c63d108cffcc77c06838aa5e018f9684a1e3908ceff55af7efa7c39..fb1c53dbf42205d315ea19be16226d174cc3736acf8532dc368c04ab51f426b7 100644
--- a/doc/INSTALL
+++ b/doc/INSTALL
@@ -7,7 +7,7 @@ => https://go.dev/ Go
 => https://opus-codec.org/ libopus
 => https://wiki.hydrogenaud.io/index.php?title=Opus Opus improvements
 => https://github.com/hraban/opus gopkg.in/hraban/opus.v2
-=> https://opus-codec.org/demo/opus-1.5/ ML-related optimisations
+=> https://opus-codec.org/demo/opus-1.6/ ML-related optimisations
 
 Audio recording and playback is done through external utilities, capable
 of reading/writing raw audio samples from stdin/stdout. SoX'es rec and
@@ -16,12 +16,15 @@ them with -rec and -play options to vors-client.
 
 => https://sourceforge.net/projects/sox/ SoX
 
-    $ version=6.0.0
+    $ version=6.3.0
     $ [fetch|wget] http://www.vors.stargrave.org/download/vors-$version.tar.zst
     $ [fetch|wget] http://www.vors.stargrave.org/download/vors-$version.tar.zst.sig
     [verify signature]
+    $ [fetch|wget] https://downloads.xiph.org/releases/opus/opus-1.6.tar.gz
+    $ [ "$(sha512 <opus-1.6.tar.gz)" = "23a71d6ed610d35742c990902eb2c7b17f28fb8d38677193f984e3ad7ed506c816062f241af5d8ab901cc91d0ddb890b774efac3867a7cef2d53d26464ea7df3" ]
     $ tar xf vors-$version.tar.zst
     $ cd vors-$version
+    $ ln -s ../opus-1.6.tar.gz
     $ ./build
     $ mv bin/vors-* $PATH/bin
 
diff --git a/internal/version.go b/internal/version.go
index 44272b6a77ead97a8210a2c2ac5d045fbcacd3db0eb5828ad7f29bfe44dad602..3a3f27818e2ebaa7fc2257bd72f0789a15a82afb61c0023946adcfa1d49b85e1 100644
--- a/internal/version.go
+++ b/internal/version.go
@@ -3,7 +3,7 @@
 import "runtime"
 
 const (
-	Version  = "6.2.0"
+	Version  = "6.3.0"
 	Warranty = `Copyright (C) 2024-2025 Sergey Matveev
 
 This program is free software: you can redistribute it and/or modify
diff --git a/makedist b/makedist
index 61beb15d799bd76e454b257d7967abdf9c680dca0ddb30c3407a741d9bf2765d..081eab04afc9d1f0489d4e776a867e252bf7b4ea7ae59bc5f7f0fe07fc9b047d 100755
--- a/makedist
+++ b/makedist
@@ -27,7 +27,6 @@ find . \( -name .gitignore -o -name .travis.yml \) -delete
 
 ########################################################################
 
-gunzip <$cur/opus-1.5.2.tar.gz >opus-1.5.2.tar
 rm -rf .git makedist
 find . -type d -exec chmod 755 {} +
 find . -type f -exec chmod 644 {} +