diff --git a/ChangeLog b/ChangeLog
index d3b5fc7f..0d1ed3d9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2021-11-16  Jay Berkenbilt  <ejb@ql.org>
+
+	* 10.4.0: release
+
 2021-11-10  Jay Berkenbilt  <ejb@ql.org>
 
 	* Add --allow-weak-crypto option to suppress warnings about use of
diff --git a/autofiles.sums b/autofiles.sums
index ccf1761d..6d0367a3 100644
--- a/autofiles.sums
+++ b/autofiles.sums
@@ -1,4 +1,4 @@
-fc6b711799de9683bac96ff6951b2cb55793094652968d33069cbf41014a7808  configure.ac
+e8f33e2b17d8c04fc1c160e9a92e7f1e48e433467f734629cdbb873f2d6fa676  configure.ac
 d3f9ee6f6f0846888d9a10fd3dad2e4b1258be84205426cf04d7cef02d61dad7  aclocal.m4
 c12d837479fa9a3fa4c278b6dc7d6b449503d663e0f0d294305595a51ff43f70  libqpdf/qpdf/qpdf-config.h.in
 5297971a0ef90bcd5563eb3f7127a032bb76d3ae2af7258bf13479caf8983a60  m4/ax_cxx_compile_stdcxx.m4
diff --git a/configure b/configure
index 6e8b7161..ce153db2 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.69 for qpdf 10.3.2.
+# Generated by GNU Autoconf 2.69 for qpdf 10.4.0.
 #
 #
 # Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
@@ -587,8 +587,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='qpdf'
 PACKAGE_TARNAME='qpdf'
-PACKAGE_VERSION='10.3.2'
-PACKAGE_STRING='qpdf 10.3.2'
+PACKAGE_VERSION='10.4.0'
+PACKAGE_STRING='qpdf 10.4.0'
 PACKAGE_BUGREPORT=''
 PACKAGE_URL=''
 
@@ -1377,7 +1377,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures qpdf 10.3.2 to adapt to many kinds of systems.
+\`configure' configures qpdf 10.4.0 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1443,7 +1443,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of qpdf 10.3.2:";;
+     short | recursive ) echo "Configuration of qpdf 10.4.0:";;
    esac
   cat <<\_ACEOF
 
@@ -1629,7 +1629,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-qpdf configure 10.3.2
+qpdf configure 10.4.0
 generated by GNU Autoconf 2.69
 
 Copyright (C) 2012 Free Software Foundation, Inc.
@@ -2298,7 +2298,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by qpdf $as_me 10.3.2, which was
+It was created by qpdf $as_me 10.4.0, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   $ $0 $@
@@ -16328,9 +16328,9 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 # * Otherwise, increment LT_REVISION
 
 # LT = libtool
-LT_CURRENT=31
-LT_AGE=3
-LT_REVISION=2
+LT_CURRENT=32
+LT_AGE=4
+LT_REVISION=0
 
 
 
@@ -19295,7 +19295,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by qpdf $as_me 10.3.2, which was
+This file was extended by qpdf $as_me 10.4.0, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -19361,7 +19361,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-qpdf config.status 10.3.2
+qpdf config.status 10.4.0
 configured by $0, generated by GNU Autoconf 2.69,
   with options \\"\$ac_cs_config\\"
 
diff --git a/configure.ac b/configure.ac
index 76891e07..8d81ac3a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2,7 +2,7 @@ dnl Process this file with autoconf to produce a configure script.
 dnl This config.in requires autoconf 2.5 or greater.
 
 AC_PREREQ([2.68])
-AC_INIT([qpdf],[10.3.2])
+AC_INIT([qpdf],[10.4.0])
 
 AC_CONFIG_MACRO_DIR([m4])
 AC_CONFIG_FILES([autoconf.mk])
@@ -52,9 +52,9 @@ LT_INIT([win32-dll])
 # * Otherwise, increment LT_REVISION
 
 # LT = libtool
-LT_CURRENT=31
-LT_AGE=3
-LT_REVISION=2
+LT_CURRENT=32
+LT_AGE=4
+LT_REVISION=0
 AC_SUBST(LT_CURRENT)
 AC_SUBST(LT_REVISION)
 AC_SUBST(LT_AGE)
diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc
index 4ce60ea2..f031eb5a 100644
--- a/libqpdf/QPDF.cc
+++ b/libqpdf/QPDF.cc
@@ -25,7 +25,7 @@
 #include <qpdf/QPDF_Stream.hh>
 #include <qpdf/QPDF_Array.hh>
 
-std::string QPDF::qpdf_version = "10.3.2";
+std::string QPDF::qpdf_version = "10.4.0";
 
 static char const* EMPTY_PDF =
     "%PDF-1.3\n"
diff --git a/manual/qpdf-manual.xml b/manual/qpdf-manual.xml
index 98ce8afa..7ce5d034 100644
--- a/manual/qpdf-manual.xml
+++ b/manual/qpdf-manual.xml
@@ -5,8 +5,8 @@
 <!ENTITY mdash "&#x2014;">
 <!ENTITY ndash "&#x2013;">
 <!ENTITY nbsp "&#xA0;">
-<!ENTITY swversion "10.3.2">
-<!ENTITY lastreleased "May 8, 2021">
+<!ENTITY swversion "10.4.0">
+<!ENTITY lastreleased "November 16, 2021">
 ]>
 <book>
  <bookinfo>
@@ -5117,7 +5117,7 @@ print "\n";
    </varlistentry>
 -->
    <varlistentry>
-    <term>10.4.0: Month dd, YYYY</term>
+    <term>10.4.0: November 16, 2021</term>
     <listitem>
      <itemizedlist>
       <listitem>
diff --git a/qpdf/qpdf.cc b/qpdf/qpdf.cc
index f3fdfbc4..8e91e20b 100644
--- a/qpdf/qpdf.cc
+++ b/qpdf/qpdf.cc
@@ -40,7 +40,7 @@ static int constexpr EXIT_CORRECT_PASSWORD = 3;
 
 static char const* whoami = 0;
 
-static std::string expected_version = "10.3.2";
+static std::string expected_version = "10.4.0";
 
 struct PageSpec
 {