diff --git a/CHANGELOG.md b/CHANGELOG.md
index dd5769e..bab491a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # Changelog
 
-## [Unreleased]
+## [0.51.1] - 2022-09-18
 
 ### Fixed
 
diff --git a/configure b/configure
index 03c801d..3996479 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 lbdb 0.51.
+# Generated by GNU Autoconf 2.69 for lbdb 0.51.1.
 #
 # Report bugs to <roland@spinnaker.de>.
 #
@@ -580,8 +580,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='lbdb'
 PACKAGE_TARNAME='lbdb'
-PACKAGE_VERSION='0.51'
-PACKAGE_STRING='lbdb 0.51'
+PACKAGE_VERSION='0.51.1'
+PACKAGE_STRING='lbdb 0.51.1'
 PACKAGE_BUGREPORT='roland@spinnaker.de'
 PACKAGE_URL='https://www.spinnaker.de/lbdb/'
 
@@ -1303,7 +1303,7 @@ 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 lbdb 0.51 to adapt to many kinds of systems.
+\`configure' configures lbdb 0.51.1 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1369,7 +1369,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of lbdb 0.51:";;
+     short | recursive ) echo "Configuration of lbdb 0.51.1:";;
    esac
   cat <<\_ACEOF
 
@@ -1479,7 +1479,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-lbdb configure 0.51
+lbdb configure 0.51.1
 generated by GNU Autoconf 2.69
 
 Copyright (C) 2012 Free Software Foundation, Inc.
@@ -1781,7 +1781,7 @@ 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 lbdb $as_me 0.51, which was
+It was created by lbdb $as_me 0.51.1, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   $ $0 $@
@@ -7254,7 +7254,7 @@ cat >>$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 lbdb $as_me 0.51, which was
+This file was extended by lbdb $as_me 0.51.1, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -7312,7 +7312,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-lbdb config.status 0.51
+lbdb config.status 0.51.1
 configured by $0, generated by GNU Autoconf 2.69,
   with options \\"\$ac_cs_config\\"
 
diff --git a/configure.ac b/configure.ac
index ebf8599..5022ba2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -15,7 +15,7 @@ dnl along with this program; if not, write to the Free Software Foundation,
 dnl Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 
 AC_INIT([lbdb],
-	0.51,
+	0.51.1,
 	[roland@spinnaker.de],
 	[],
 	[https://www.spinnaker.de/lbdb/])
diff --git a/tests/package.m4 b/tests/package.m4
index 58e8498..ae2fecd 100644
--- a/tests/package.m4
+++ b/tests/package.m4
@@ -1,6 +1,6 @@
 # Signature of the current package.
 m4_define([AT_PACKAGE_NAME],	  [lbdb])
 m4_define([AT_PACKAGE_TARNAME],	  [lbdb])
-m4_define([AT_PACKAGE_VERSION],	  [0.51])
-m4_define([AT_PACKAGE_STRING],	  [lbdb 0.51])
+m4_define([AT_PACKAGE_VERSION],	  [0.51.1])
+m4_define([AT_PACKAGE_STRING],	  [lbdb 0.51.1])
 m4_define([AT_PACKAGE_BUGREPORT], [roland@spinnaker.de])
diff --git a/tests/testsuite b/tests/testsuite
index faa2326..4702518 100755
--- a/tests/testsuite
+++ b/tests/testsuite
@@ -909,7 +909,7 @@ fi
 # List of tests.
 if $at_list_p; then
   cat <<_ATEOF || at_write_fail=1
-lbdb 0.51 test suite test groups:
+lbdb 0.51.1 test suite test groups:
 
  NUM: FILE-NAME:LINE     TEST-GROUP-NAME
       KEYWORDS
@@ -950,7 +950,7 @@ _ATEOF
   exit $at_write_fail
 fi
 if $at_version_p; then
-  $as_echo "$as_me (lbdb 0.51)" &&
+  $as_echo "$as_me (lbdb 0.51.1)" &&
   cat <<\_ATEOF || at_write_fail=1
 
 Copyright (C) 2012 Free Software Foundation, Inc.
@@ -1135,13 +1135,13 @@ fi
 exec 5>>"$at_suite_log"
 
 # Banners and logs.
-$as_echo "## --------------------- ##
-## lbdb 0.51 test suite. ##
-## --------------------- ##"
+$as_echo "## ----------------------- ##
+## lbdb 0.51.1 test suite. ##
+## ----------------------- ##"
 {
-  $as_echo "## --------------------- ##
-## lbdb 0.51 test suite. ##
-## --------------------- ##"
+  $as_echo "## ----------------------- ##
+## lbdb 0.51.1 test suite. ##
+## ----------------------- ##"
   echo
 
   $as_echo "$as_me: command line was:"
@@ -1984,7 +1984,7 @@ _ASBOX
   $as_echo "Please send $at_msg and all information you think might help:
 
    To: <roland@spinnaker.de>
-   Subject: [lbdb 0.51] $as_me: $at_fail_list${at_fail_list:+ failed${at_xpass_list:+, }}$at_xpass_list${at_xpass_list:+ passed unexpectedly}
+   Subject: [lbdb 0.51.1] $as_me: $at_fail_list${at_fail_list:+ failed${at_xpass_list:+, }}$at_xpass_list${at_xpass_list:+ passed unexpectedly}
 
 You may investigate any problem if you feel able to do so, in which
 case the test suite provides a good starting point.  Its output may