diff --git a/.github/workflows/docker.yml b/.github/workflows/docker.yml
index 0d3696f..36aba5c 100644
--- a/.github/workflows/docker.yml
+++ b/.github/workflows/docker.yml
@@ -20,8 +20,8 @@ jobs:
           - 'ubuntu-20.04'
           - 'alpine-3.17'
         package_ruby_ver:
-          - '3.2.5'
-          - '3.3.4'
+          - '3.2.6'
+          - '3.3.6'
     container:
       image: ghcr.io/tamatebako/tebako-${{ matrix.container }}:latest
     steps:
@@ -67,7 +67,7 @@ jobs:
           - 'ubuntu-20.04'
           - 'alpine-3.17'
         package_ruby_ver:
-          - '3.2.5'
+          - '3.2.6'
     container:
       image: ghcr.io/tamatebako/tebako-${{ matrix.container }}:latest
     steps:
diff --git a/.github/workflows/rhel.yml b/.github/workflows/rhel.yml
index cf333a1..2611bf5 100644
--- a/.github/workflows/rhel.yml
+++ b/.github/workflows/rhel.yml
@@ -47,7 +47,7 @@ jobs:
         run: |
           docker run -v $PWD:/mnt/w -t ghcr.io/tamatebako/tebako-ubuntu-20.04:latest \
                          tebako press --root=/mnt/w/sinatra --entry-point=app.rb     \
-                         --output=/mnt/w/sinatra.tebako --Ruby=3.2.5 --patchelf
+                         --output=/mnt/w/sinatra.tebako --Ruby=3.2.6 --patchelf
 
       - name: Upload tebako test packages
         uses: actions/upload-artifact@v4
@@ -116,7 +116,7 @@ jobs:
         run: |
           docker run -v $PWD:/mnt/w -t ghcr.io/tamatebako/tebako-ubuntu-20.04:latest \
                          tebako press --root=/mnt/w/ror --entry-point=bin/rails     \
-                         --output=/mnt/w/rails.tebako --Ruby=3.2.5 --patchelf
+                         --output=/mnt/w/rails.tebako --Ruby=3.2.6 --patchelf
 
       - name: Upload tebako test packages
         uses: actions/upload-artifact@v4
diff --git a/README.adoc b/README.adoc
index 189e673..d243a49 100644
--- a/README.adoc
+++ b/README.adoc
@@ -58,7 +58,7 @@ Packaging from inside the container:
 
 [source,sh]
 ----
-tebako press -e app.rb -o sinatra.teb -r sinatra -R 3.2.5
+tebako press -e app.rb -o sinatra.teb -r sinatra -R 3.2.6
 ----
 
 Packaging from outside the container for Ubuntu:
@@ -67,7 +67,7 @@ Packaging from outside the container for Ubuntu:
 ----
 docker run -v $PWD:/mnt/w -t ghcr.io/tamatebako/tebako-ubuntu-20.04:latest \
   tebako press --root=/mnt/w/sinatra --entry-point=app.rb \
-  --output=/mnt/w/sinatra.tebako --Ruby=3.2.5 --patchelf
+  --output=/mnt/w/sinatra.tebako --Ruby=3.2.6 --patchelf
 ----
 
 This command:
@@ -93,7 +93,7 @@ Packaging from outside the container for Alpine:
 ----
 docker run -v $PWD:/mnt/w -t ghcr.io/tamatebako/tebako-alpine-3.17:latest \
   tebako press --root=/mnt/w/sinatra --entry-point=app.rb \
-  --output=/mnt/w/sinatra.tebako --Ruby=3.2.5
+  --output=/mnt/w/sinatra.tebako --Ruby=3.2.6
 ----
 
 === Packaging for glibc-based Linux distributions using the Ubuntu container
@@ -182,7 +182,7 @@ For example, packaging from outside the container for Ubuntu:
 ----
 docker run -v $PWD:/mnt/w -t ghcr.io/tamatebako/tebako-ubuntu-20.04:latest \
   tebako press --root=/mnt/w/ror --entry-point=bin/rails \
-  --output=/mnt/w/rails.tebako --Ruby=3.2.5 --patchelf
+  --output=/mnt/w/rails.tebako --Ruby=3.2.6 --patchelf
 ----
 
 Please refer to Sinatra sample comments above for more Tebako CI containers examples.
diff --git a/ror/.ruby-version b/ror/.ruby-version
index 5ae69bd..34cde56 100644
--- a/ror/.ruby-version
+++ b/ror/.ruby-version
@@ -1 +1 @@
-3.2.5
+3.2.6
diff --git a/ror/Gemfile b/ror/Gemfile
index d67e64d..e4d038a 100644
--- a/ror/Gemfile
+++ b/ror/Gemfile
@@ -1,6 +1,6 @@
 source "https://rubygems.org"
 
-ruby "3.2.5"
+ruby "3.2.6"
 
 # Bundle edge Rails instead: gem "rails", github: "rails/rails", branch: "main"
 gem "rails", "~> 7.1.3", ">= 7.1.3.4"
diff --git a/tutorial/1_hello_world/sample/hello_world.rb b/tutorial/1_hello_world/sample/hello_world.rb
index dd8beac..b4b42b5 100644
--- a/tutorial/1_hello_world/sample/hello_world.rb
+++ b/tutorial/1_hello_world/sample/hello_world.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-# Copyright (c) 2023-2025 [Ribose Inc](https://www.ribose.com).
+# Copyright (c) 2025 [Ribose Inc](https://www.ribose.com).
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without