diff --git a/.github/workflows/gem.yaml b/.github/workflows/gem.yaml
new file mode 100644
index 0000000..aac7911
--- /dev/null
+++ b/.github/workflows/gem.yaml
@@ -0,0 +1,30 @@
+name: Gem
+on:
+  push:
+    tags:
+      - 'v*.*.*'
+
+jobs:
+  gem-push:
+    runs-on: ubuntu-latest
+    permissions:
+      # https://docs.github.com/en/actions/reference/authentication-in-a-workflow
+      packages: write
+    steps:
+    - uses: actions/checkout@v2
+    - name: Publish Gem package
+      env:
+        GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
+      # Inspired by https://github.com/bodyshopbidsdotcom/gh-action-publish-gem-on-tag/blob/1.0.1/entrypoint.sh
+      run: |
+        GIT_VERSION=$(echo "$GITHUB_REF" | cut -d'/' -f 3-)
+        SPEC_VERSION=$(ruby -e 'require "rubygems"; gemspec = Dir.entries(".").find { |file| file =~ /.*\.gemspec/ }; spec = Gem::Specification::load(gemspec); puts spec.version')
+        if [[ "$GIT_VERSION" != "v${SPEC_VERSION}" ]]; then
+          echo "Ignoring, git tag version differs from gem spec version."
+          exit 2;
+        fi
+        mkdir -p ~/.gem
+        echo ":github: Bearer ${GITHUB_TOKEN}" > ~/.gem/credentials
+        chmod 600 ~/.gem/credentials
+        gem build *.gemspec
+        gem push --key github --host "https://rubygems.pkg.github.com/${{ github.repository_owner }}" *.gem
diff --git a/Gemfile b/Gemfile
index abe254d..49b345c 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,18 +1,6 @@
 source "https://rubygems.org"
 ruby RUBY_VERSION
 
-gem "jekyll", "~> 4.2.0"
-gem "kramdown-parser-gfm", "1.1.0"
-gem "jekyll-redirect-from", "~> 0.16.0", group: :jekyll_plugins
-gem "jekyll-relative-links", "~> 0.6.1", group: :jekyll_plugins
-gem "jekyll-remote-theme", "~> 0.4.3", group: :jekyll_plugins
+gemspec
 
-# Blog
-gem "jekyll-feed", "~> 0.15.1", group: :jekyll_plugins
-gem "jekyll-archives", "~> 2.2.1", group: :jekyll_plugins
-
-# Search
 gem "jekyll-algolia", "~> 1.7.0", group: :jekyll_plugins
-
-# Temporary fix until there is a release with https://github.com/jekyll/jekyll/pull/8524/
-gem "webrick", "~> 1.7"
diff --git a/README.md b/README.md
index e1a8eec..788c6fb 100644
--- a/README.md
+++ b/README.md
@@ -22,13 +22,7 @@ Requirements:
 * [Ruby](https://www.ruby-lang.org/) (tested with Ruby 2.7+)
 * [Bundler](https://bundler.io/) (if missing, install with `gem install bundler`)
 
-To install Jekyll and plugins the first time:
-
-```shell
-bundle install
-```
-
-To update Jekyll and any plugins (e.g. after changing `Gemfile`):
+To install or update Jekyll and plugins:
 
 ```shell
 bundle update
diff --git a/_config.yml b/_config.yml
index 12b64eb..fbc4cd2 100644
--- a/_config.yml
+++ b/_config.yml
@@ -19,15 +19,6 @@ baseurl: /jekyll-theme-amethyst
 permalink: /:year/:month/:day/:title/
 lang: en
 timezone: UTC
-# Disable theme inheritance since this repo contains its own theme top-level theme.
-# This isn't needed for plain Jekyll, but because we use github-pages as basis
-# we otherwise inherit from the 'primer' theme.
-# This is a problem because, Jekyll/Sass/Primer fails to compile by default, yay.
-# - https://github.com/jekyll/jekyll/issues/7426
-# - https://github.com/jekyll/jekyll/issues/4268
-# - https://github.com/sindresorhus/gulp-ruby-sass/issues/232
-# – Workaround: https://github.com/github/pages-gem/issues/613
-theme: null
 # Files that will not be converted or published
 exclude:
   # Exclude repo docs from site output and search index
@@ -45,6 +36,7 @@ exclude:
 # Amethyst theme options are documented at:
 # https://github.com/qunitjs/jekyll-theme-amethyst/blob/main/docs/config.md
 #
+theme: jekyll-theme-amethyst
 amethyst:
   edituri_base: https://github.com/qunitjs/jekyll-theme-amethyst/blob/main/
   release_base: https://github.com/qunitjs/qunit/releases/tag/
diff --git a/amethyst.gemspec b/amethyst.gemspec
new file mode 100644
index 0000000..0a7df5a
--- /dev/null
+++ b/amethyst.gemspec
@@ -0,0 +1,23 @@
+Gem::Specification.new do |spec|
+  spec.name     = "jekyll-theme-amethyst"
+  spec.version  = "0.1.1"
+  spec.summary  = "https://github.com/qunitjs/jekyll-theme-amethyst"
+  spec.authors  = ["Timo Tijhof", "Trent Willis"]
+  spec.files    = `git ls-files -z`.split("\x0")
+
+  spec.license   = "MIT"
+  spec.homepage  = "https://github.com/qunitjs/jekyll-theme-amethyst"
+
+  spec.metadata["plugin_type"] = "theme"
+  spec.require_paths = ["lib"]
+
+  spec.add_runtime_dependency "jekyll", ">= 4.2", "< 5.0"
+  spec.add_runtime_dependency "kramdown-parser-gfm", "~> 1.1.0"
+  spec.add_runtime_dependency "jekyll-redirect-from", "~> 0.16.0"
+  spec.add_runtime_dependency "jekyll-relative-links", "~> 0.6.1"
+  # For blog
+  spec.add_runtime_dependency "jekyll-feed", "~> 0.15.1"
+  spec.add_runtime_dependency "jekyll-archives", "~> 2.2.1"
+  # Temporary fix until there is a release with https://github.com/jekyll/jekyll/pull/8524/
+  spec.add_runtime_dependency "webrick", "~> 1.7"
+end