diff --git a/.github/workflows/ci-cd.yaml b/.github/workflows/ci-cd.yaml
index 98e6a15..25be8ad 100644
--- a/.github/workflows/ci-cd.yaml
+++ b/.github/workflows/ci-cd.yaml
@@ -11,7 +11,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby-version: ['3.1', '3.2', '3.3', '3.4', 'jruby']
+        ruby-version: ['3.2', '3.3', '3.4', '4.0', 'jruby']
         os: [ubuntu-latest, macOS-latest, windows-latest]
         # experimental: [false]
         include:
@@ -27,7 +27,7 @@ jobs:
             os: ubuntu-latest
             experimental: false
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
 
     - name: Set up ruby ${{ matrix.ruby-version }}
       uses: ruby/setup-ruby@v1
@@ -49,9 +49,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby-version: [
-          "3.1", "3.4"
-        ]
+        ruby-version: ['3.2', '3.3', '3.4', '4.0', 'jruby']
         os: [
           ubuntu-latest,
           macOS-latest,
@@ -59,7 +57,7 @@ jobs:
           # windows-latest
         ]
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - name: Set up ruby ${{ matrix.ruby-version }}
       uses: ruby/setup-ruby@v1
       with:
@@ -82,11 +80,11 @@ jobs:
     needs: [Unit_tests, Integration_tests]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - name: Set up Ruby 3.4
+      - uses: actions/checkout@v5
+      - name: Setup Ruby 4.0
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: 3.4
+          ruby-version: 4.0
       - name: Check if properly tagged
         run: |
           PACKAGE_VERSION="$(ruby -e 'puts Gem::Specification::load("tinify.gemspec").version')";
diff --git a/.ruby-version b/.ruby-version
new file mode 100644
index 0000000..1454f6e
--- /dev/null
+++ b/.ruby-version
@@ -0,0 +1 @@
+4.0.1
diff --git a/CHANGELOG.md b/CHANGELOG.md
index ec8a28e..1aef02f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,15 @@
+## 1.8.0
+
+* Update development dependencies.
+
+Extend runtime support for:
+
+* Ruby 4.0
+
+Remove runtime support for:
+
+* Ruby 3.1
+
 ## 1.7.1
 * Update `rexml` because of `CVE-2025-58767`.
 * Fix source `:result` to use post when a body is given.
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..a5559d6
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,18 @@
+FROM "docker.io/ruby:4.0-alpine"
+
+ARG UID=1000
+ARG GID=1000
+
+RUN addgroup -g "$GID" -S 'app' \
+      && adduser -u "$UID" -G 'app' -S 'app'
+
+WORKDIR /home/app
+
+COPY --chown=app:app . .
+
+RUN apk add --no-cache --update alpine-sdk yaml-dev \
+      && bundle install \
+      && chown -R app:app /usr/local/bundle
+
+ENTRYPOINT /bin/sh
+USER app
diff --git a/Gemfile.lock b/Gemfile.lock
index 75a30d6..fff08fd 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,29 +1,31 @@
 PATH
   remote: .
   specs:
-    tinify (1.7.1)
+    tinify (1.8.0)
       httpclient (>= 2.9, < 3)
 
 GEM
   remote: https://rubygems.org/
   specs:
-    addressable (2.8.7)
-      public_suffix (>= 2.0.2, < 7.0)
+    addressable (2.8.8)
+      public_suffix (>= 2.0.2, < 8.0)
     base64 (0.3.0)
-    bigdecimal (3.2.3)
-    bigdecimal (3.2.3-java)
-    crack (1.0.0)
+    bigdecimal (4.0.1)
+    bigdecimal (4.0.1-java)
+    crack (1.0.1)
       bigdecimal
       rexml
     hashdiff (1.2.1)
     httpclient (2.9.0)
       mutex_m
-    minitest (5.25.5)
+    minitest (6.0.1)
+      prism (~> 1.5)
     mutex_m (0.3.0)
-    public_suffix (6.0.2)
-    rake (13.3.0)
+    prism (1.8.0)
+    public_suffix (7.0.2)
+    rake (13.3.1)
     rexml (3.4.4)
-    webmock (3.25.1)
+    webmock (3.26.1)
       addressable (>= 2.8.0)
       crack (>= 0.3.2)
       hashdiff (>= 0.4.0, < 2.0.0)
diff --git a/lib/tinify/version.rb b/lib/tinify/version.rb
index 2e36876..472ed08 100644
--- a/lib/tinify/version.rb
+++ b/lib/tinify/version.rb
@@ -1,3 +1,3 @@
 module Tinify
-  VERSION = "1.7.1"
+  VERSION = "1.8.0"
 end