diff --git a/ChangeLog b/ChangeLog
index e5018320..89f9ed25 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2010-01-17  Tatsuhiro Tsujikawa  <t-tujikawa@users.sourceforge.net>
+
+	Bump up version number to 1.8.1
+	* configure.ac
+
 2010-01-17  Tatsuhiro Tsujikawa  <t-tujikawa@users.sourceforge.net>
 
 	Added version number to man page. Updated copyright year in man
diff --git a/configure b/configure
index e35b85bb..ba168c59 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.65 for aria2 1.8.0.
+# Generated by GNU Autoconf 2.65 for aria2 1.8.1.
 #
 # Report bugs to <t-tujikawa@users.sourceforge.net>.
 #
@@ -552,8 +552,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='aria2'
 PACKAGE_TARNAME='aria2'
-PACKAGE_VERSION='1.8.0'
-PACKAGE_STRING='aria2 1.8.0'
+PACKAGE_VERSION='1.8.1'
+PACKAGE_STRING='aria2 1.8.1'
 PACKAGE_BUGREPORT='t-tujikawa@users.sourceforge.net'
 PACKAGE_URL='http://aria2.sourceforge.net/'
 
@@ -1424,7 +1424,7 @@ 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 aria2 1.8.0 to adapt to many kinds of systems.
+\`configure' configures aria2 1.8.1 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1495,7 +1495,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of aria2 1.8.0:";;
+     short | recursive ) echo "Configuration of aria2 1.8.1:";;
    esac
   cat <<\_ACEOF
 
@@ -1641,7 +1641,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-aria2 configure 1.8.0
+aria2 configure 1.8.1
 generated by GNU Autoconf 2.65
 
 Copyright (C) 2009 Free Software Foundation, Inc.
@@ -2468,7 +2468,7 @@ 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 aria2 $as_me 1.8.0, which was
+It was created by aria2 $as_me 1.8.1, which was
 generated by GNU Autoconf 2.65.  Invocation command line was
 
   $ $0 $@
@@ -3392,7 +3392,7 @@ fi
 
 # Define the identity of the package.
  PACKAGE='aria2'
- VERSION='1.8.0'
+ VERSION='1.8.1'
 
 
 cat >>confdefs.h <<_ACEOF
@@ -15619,7 +15619,7 @@ 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 aria2 $as_me 1.8.0, which was
+This file was extended by aria2 $as_me 1.8.1, which was
 generated by GNU Autoconf 2.65.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -15686,7 +15686,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-aria2 config.status 1.8.0
+aria2 config.status 1.8.1
 configured by $0, generated by GNU Autoconf 2.65,
   with options \\"\$ac_cs_config\\"
 
diff --git a/configure.ac b/configure.ac
index 1c31d2dd..6ffa73a1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2,7 +2,7 @@
 # Process this file with autoconf to produce a configure script.
 #
 AC_PREREQ(2.65)
-AC_INIT([aria2],[1.8.0],[t-tujikawa@users.sourceforge.net],[aria2],[http://aria2.sourceforge.net/])
+AC_INIT([aria2],[1.8.1],[t-tujikawa@users.sourceforge.net],[aria2],[http://aria2.sourceforge.net/])
 AC_CANONICAL_HOST
 AC_CANONICAL_TARGET
 AM_INIT_AUTOMAKE()