diff --git a/SPECS/pg_bulkload-pg14.spec b/SPECS/pg_bulkload-pg14.spec
index 423f508..461a9d8 100755
--- a/SPECS/pg_bulkload-pg14.spec
+++ b/SPECS/pg_bulkload-pg14.spec
@@ -10,7 +10,7 @@
 
 Summary:        High speed data load utility for PostgreSQL
 Name:           %{sname}
-Version:        3.1.22
+Version:        3.1.23
 Release:        1%{?dist}
 License:        BSD
 Group:          Applications/Databases
@@ -93,6 +93,9 @@ rm -rf %{buildroot}
 rm -rf %{_libdir}/pgxs/src/backend/
 
 %changelog
+* Tue Jan 13 2026 - NTT OSS Center <shinya11.kato@gmail.com> 3.1.23-1
+- Support PostgreSQL 18
+- Update to pg_bulkload 3.1.23
 * Thu Jan 23 2025 - NTT OSS Center <zuowei.yan.tb@hco.ntt.co.jp> 3.1.22-1
 - Support PostgreSQL 17
 - Update to pg_bulkload 3.1.22
diff --git a/SPECS/pg_bulkload-pg15.spec b/SPECS/pg_bulkload-pg15.spec
index 99501f2..89735df 100755
--- a/SPECS/pg_bulkload-pg15.spec
+++ b/SPECS/pg_bulkload-pg15.spec
@@ -10,7 +10,7 @@
 
 Summary:        High speed data load utility for PostgreSQL
 Name:           %{sname}
-Version:        3.1.22
+Version:        3.1.23
 Release:        1%{?dist}
 License:        BSD
 Group:          Applications/Databases
@@ -93,6 +93,9 @@ rm -rf %{buildroot}
 rm -rf %{_libdir}/pgxs/src/backend/
 
 %changelog
+* Tue Jan 13 2026 - NTT OSS Center <shinya11.kato@gmail.com> 3.1.23-1
+- Support PostgreSQL 18
+- Update to pg_bulkload 3.1.23
 * Thu Jan 23 2025 - NTT OSS Center <zuowei.yan.tb@hco.ntt.co.jp> 3.1.22-1
 - Support PostgreSQL 17
 - Update to pg_bulkload 3.1.22
diff --git a/SPECS/pg_bulkload-pg16.spec b/SPECS/pg_bulkload-pg16.spec
index 9d5d11a..444d77f 100755
--- a/SPECS/pg_bulkload-pg16.spec
+++ b/SPECS/pg_bulkload-pg16.spec
@@ -10,7 +10,7 @@
 
 Summary:        High speed data load utility for PostgreSQL
 Name:           %{sname}
-Version:        3.1.22
+Version:        3.1.23
 Release:        1%{?dist}
 License:        BSD
 Group:          Applications/Databases
@@ -93,6 +93,9 @@ rm -rf %{buildroot}
 rm -rf %{_libdir}/pgxs/src/backend/
 
 %changelog
+* Tue Jan 13 2026 - NTT OSS Center <shinya11.kato@gmail.com> 3.1.23-1
+- Support PostgreSQL 18
+- Update to pg_bulkload 3.1.23
 * Thu Jan 23 2025 - NTT OSS Center <zuowei.yan.tb@hco.ntt.co.jp> 3.1.22-1
 - Support PostgreSQL 17
 - Update to pg_bulkload 3.1.22
diff --git a/SPECS/pg_bulkload-pg17.spec b/SPECS/pg_bulkload-pg17.spec
index da52658..a2e5f1a 100755
--- a/SPECS/pg_bulkload-pg17.spec
+++ b/SPECS/pg_bulkload-pg17.spec
@@ -10,7 +10,7 @@
 
 Summary:        High speed data load utility for PostgreSQL
 Name:           %{sname}
-Version:        3.1.22
+Version:        3.1.23
 Release:        1%{?dist}
 License:        BSD
 Group:          Applications/Databases
@@ -93,6 +93,9 @@ rm -rf %{buildroot}
 rm -rf %{_libdir}/pgxs/src/backend/
 
 %changelog
+* Tue Jan 13 2026 - NTT OSS Center <shinya11.kato@gmail.com> 3.1.23-1
+- Support PostgreSQL 18
+- Update to pg_bulkload 3.1.23
 * Thu Jan 23 2025 - NTT OSS Center <zuowei.yan.tb@hco.ntt.co.jp> 3.1.22-1
 - Support PostgreSQL 17
 - Update to pg_bulkload 3.1.22
diff --git a/SPECS/pg_bulkload-pg13.spec b/SPECS/pg_bulkload-pg18.spec
similarity index 79%
rename from SPECS/pg_bulkload-pg13.spec
rename to SPECS/pg_bulkload-pg18.spec
index d35bc64..f8018b4 100755
--- a/SPECS/pg_bulkload-pg13.spec
+++ b/SPECS/pg_bulkload-pg18.spec
@@ -1,8 +1,8 @@
-# SPEC file for pg_bulkload on PostgreSQL 13
+# SPEC file for pg_bulkload on PostgreSQL 18
 # Copyright (C) 2009-2026 NTT, Inc.
 
 %define sname                   pg_bulkload
-%define pgmajorversion  13
+%define pgmajorversion  18
 
 %define _prefix                 /usr/pgsql-%{pgmajorversion}
 %define _libdir                 %{_prefix}/lib
@@ -10,7 +10,7 @@
 
 Summary:        High speed data load utility for PostgreSQL
 Name:           %{sname}
-Version:        3.1.22
+Version:        3.1.23
 Release:        1%{?dist}
 License:        BSD
 Group:          Applications/Databases
@@ -19,8 +19,8 @@ Source0:        %{sname}-%{version}.tar.gz
 URL:            http://ossc-db.github.io/pg_bulkload/index.html
 BuildRoot:      %{_tmppath}/%{name}-%{version}-%{release}-%(%{__id_u} -n)
 
-BuildRequires:  postgresql13-devel, postgresql13
-Requires:       postgresql13
+BuildRequires:  postgresql18-devel, postgresql18
+Requires:       postgresql18
 
 
 %description
@@ -30,7 +30,7 @@ When we load huge amount of data to a database, it is common situation that data
 
 
 %package llvmjit
-Requires: postgresql13-server, postgresql13-llvmjit
+Requires: postgresql18-server, postgresql18-llvmjit
 Requires: pg_bulkload = %{version}
 Summary:  Just-in-time compilation support for pg_bulkload
 
@@ -93,16 +93,6 @@ rm -rf %{buildroot}
 rm -rf %{_libdir}/pgxs/src/backend/
 
 %changelog
-* Thu Jan 23 2025 - NTT OSS Center <zuowei.yan.tb@hco.ntt.co.jp> 3.1.22-1
-- Support PostgreSQL 17
-- Update to pg_bulkload 3.1.22
-* Thu Jan 16 2024 - NTT OSS Center <zuowei.yan.tb@hco.ntt.co.jp> 3.1.21-1
-- Update to pg_bulkload 3.1.21
-* Thu Jan 13 2023 - NTT OSS Center <zuowei.yan.tb@hco.ntt.co.jp> 3.1.20-1
-- Update to pg_bulkload 3.1.20
-* Mon Oct 11 2021 - Masahiro ikeda <masahiro.ikeda.us@hco.ntt.co.jp> 3.1.19-1
-- Update to pg_bulkload 3.1.19
-* Tue Jun 01 2021 - Yanmei Sun <yanmei.sun.ep@hco.ntt.co.jp> 3.1.18-1
-- Update to pg_bulkload 3.1.18
-* Fri Feb 05 2021 - Moon Insung <insung.moon.gk@hco.ntt.co.jp> 3.1.17-1
-- Update to pg_bulkload 3.1.17
+* Tue Jan 13 2026 - NTT OSS Center <shinya11.kato@gmail.com> 3.1.23-1
+- Support PostgreSQL 18
+- Update to pg_bulkload 3.1.23
\ No newline at end of file
diff --git a/docs/pg_bulkload-ja.html b/docs/pg_bulkload-ja.html
index c29a92e..a783dfc 100644
--- a/docs/pg_bulkload-ja.html
+++ b/docs/pg_bulkload-ja.html
@@ -800,13 +800,20 @@ <h2 id="upgrade">アップグレード方法</h2>
 <h2 id="requirement">動作環境</h2>
 <dl>
 <dt>PostgreSQLバージョン</dt>
-<dd>PostgreSQL 13, 14, 15, 16, 17</dd>
+<dd>PostgreSQL 14, 15, 16, 17, 18</dd>
 <dt>OS</dt>
-<dd>RHEL 8, 9</dd>
+<dd>RHEL 8, 9, 10</dd>
 </dl>
 
 <h2 id="releasenote">リリースノート</h2>
 
+<p>
+<h4>3.1.23</h4>
+<ul>
+<li>PostgreSQL 18に対応</li>
+</ul>
+</p>
+
 <p>
 <h4>3.1.22</h4>
 <ul>
diff --git a/docs/pg_bulkload.html b/docs/pg_bulkload.html
index b824dde..8bb180f 100644
--- a/docs/pg_bulkload.html
+++ b/docs/pg_bulkload.html
@@ -876,13 +876,21 @@ <h2 id="upgrade">Upgrade</h2>
 <h2 id="requirement">Requirements</h2>
 <dl>
 <dt>PostgreSQL versions</dt>
-<dd>PostgreSQL 13, 14, 15, 16, 17</dd>
+<dd>PostgreSQL 14, 15, 16, 17, 18</dd>
 <dt>OS</dt>
-<dd>RHEL 8, 9</dd>
+<dd>RHEL 8, 9, 10</dd>
 </dl>
 
 <h2 id="releasenote">Release Notes</h2>
 
+
+<p>
+<h4>3.1.23</h4>
+<ul>
+<li>Added support for PostgreSQL 18</li>
+</ul>
+</p>
+
 <p>
 <h4>3.1.22</h4>
 <ul>