diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index cdd6246..1978fc1 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -1,27 +1,32 @@
+name: tests
+
 on:
   workflow_dispatch:
   pull_request:
     branches:
       - main
-
-name: tests
-
 jobs:
-  tests:
+  test:
+    name: Ruby ${{ matrix.ruby }} / ${{ matrix.gemfile }}
     runs-on: ubuntu-latest
-    name: Ruby ${{ matrix.ruby }}
+    env:
+      BUNDLE_GEMFILE: ${{ matrix.gemfile }}
     strategy:
       matrix:
-        ruby: ['2.6', '2.7', '3.0.7']
+        gemfile:
+          - Gemfile
+          - gemfiles/rails-6-0.gemfile
+        ruby:
+          - '3.0'
+          - '2.7'
+          - '2.6'
+        exclude:
+          - ruby: '3.0'
+            gemfile: gemfiles/rails-6-0.gemfile
     steps:
-      - name: Checkout Repository
-        uses: actions/checkout@v4
-
-      - name: Set Up Ruby
-        uses: ruby/setup-ruby@v1
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
           bundler-cache: true
-
-      - name: Run Tests
-        run: bundle exec rake
+      - run: bundle exec rake
diff --git a/Gemfile b/Gemfile
index 353e43d..b007467 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,12 +1,12 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
-git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
-# Specify your gem's dependencies in simple_form-theme.gemspec.
 gemspec
 
 group :development do
   gem 'sqlite3'
 end
 
-# To use a debugger
-# gem 'byebug', group: [:development, :test]
+gem 'rails', '~> 6.1'
+gem 'simple_form', '~> 5.3.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index 7ddc8a4..cff9ab0 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,7 +2,7 @@ PATH
   remote: .
   specs:
     simple_form-theme (0.1.2)
-      rails (~> 6.1)
+      rails (>= 6.0, < 7.0)
       simple_form (~> 5.3.0)
 
 GEM
@@ -158,6 +158,8 @@ PLATFORMS
   x86_64-linux
 
 DEPENDENCIES
+  rails (~> 6.1)
+  simple_form (~> 5.3.0)
   simple_form-theme!
   sqlite3
 
diff --git a/gemfiles/rails-6-0.gemfile b/gemfiles/rails-6-0.gemfile
new file mode 100644
index 0000000..c13cf74
--- /dev/null
+++ b/gemfiles/rails-6-0.gemfile
@@ -0,0 +1,10 @@
+source 'https://rubygems.org'
+
+gemspec path: '..'
+
+group :development do
+  gem 'sqlite3'
+end
+
+gem 'rails', '~> 6.0'
+gem 'simple_form', '~> 5.3.0'
diff --git a/gemfiles/rails-6-0.gemfile.lock b/gemfiles/rails-6-0.gemfile.lock
new file mode 100644
index 0000000..2e080cf
--- /dev/null
+++ b/gemfiles/rails-6-0.gemfile.lock
@@ -0,0 +1,167 @@
+PATH
+  remote: ..
+  specs:
+    simple_form-theme (0.1.2)
+      rails (>= 6.0, < 7.0)
+      simple_form (~> 5.3.0)
+
+GEM
+  remote: https://rubygems.org/
+  specs:
+    actioncable (6.1.7.8)
+      actionpack (= 6.1.7.8)
+      activesupport (= 6.1.7.8)
+      nio4r (~> 2.0)
+      websocket-driver (>= 0.6.1)
+    actionmailbox (6.1.7.8)
+      actionpack (= 6.1.7.8)
+      activejob (= 6.1.7.8)
+      activerecord (= 6.1.7.8)
+      activestorage (= 6.1.7.8)
+      activesupport (= 6.1.7.8)
+      mail (>= 2.7.1)
+    actionmailer (6.1.7.8)
+      actionpack (= 6.1.7.8)
+      actionview (= 6.1.7.8)
+      activejob (= 6.1.7.8)
+      activesupport (= 6.1.7.8)
+      mail (~> 2.5, >= 2.5.4)
+      rails-dom-testing (~> 2.0)
+    actionpack (6.1.7.8)
+      actionview (= 6.1.7.8)
+      activesupport (= 6.1.7.8)
+      rack (~> 2.0, >= 2.0.9)
+      rack-test (>= 0.6.3)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.0, >= 1.2.0)
+    actiontext (6.1.7.8)
+      actionpack (= 6.1.7.8)
+      activerecord (= 6.1.7.8)
+      activestorage (= 6.1.7.8)
+      activesupport (= 6.1.7.8)
+      nokogiri (>= 1.8.5)
+    actionview (6.1.7.8)
+      activesupport (= 6.1.7.8)
+      builder (~> 3.1)
+      erubi (~> 1.4)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.1, >= 1.2.0)
+    activejob (6.1.7.8)
+      activesupport (= 6.1.7.8)
+      globalid (>= 0.3.6)
+    activemodel (6.1.7.8)
+      activesupport (= 6.1.7.8)
+    activerecord (6.1.7.8)
+      activemodel (= 6.1.7.8)
+      activesupport (= 6.1.7.8)
+    activestorage (6.1.7.8)
+      actionpack (= 6.1.7.8)
+      activejob (= 6.1.7.8)
+      activerecord (= 6.1.7.8)
+      activesupport (= 6.1.7.8)
+      marcel (~> 1.0)
+      mini_mime (>= 1.1.0)
+    activesupport (6.1.7.8)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 1.6, < 2)
+      minitest (>= 5.1)
+      tzinfo (~> 2.0)
+      zeitwerk (~> 2.3)
+    builder (3.3.0)
+    concurrent-ruby (1.3.3)
+    crass (1.0.6)
+    date (3.3.4)
+    erubi (1.13.0)
+    globalid (1.2.1)
+      activesupport (>= 6.1)
+    i18n (1.14.5)
+      concurrent-ruby (~> 1.0)
+    loofah (2.22.0)
+      crass (~> 1.0.2)
+      nokogiri (>= 1.12.0)
+    mail (2.8.1)
+      mini_mime (>= 0.1.1)
+      net-imap
+      net-pop
+      net-smtp
+    marcel (1.0.4)
+    method_source (1.1.0)
+    mini_mime (1.1.5)
+    mini_portile2 (2.8.7)
+    minitest (5.24.1)
+    net-imap (0.3.7)
+      date
+      net-protocol
+    net-pop (0.1.2)
+      net-protocol
+    net-protocol (0.2.2)
+      timeout
+    net-smtp (0.5.0)
+      net-protocol
+    nio4r (2.7.3)
+    nokogiri (1.13.10-x86_64-linux)
+      racc (~> 1.4)
+    racc (1.8.0)
+    rack (2.2.9)
+    rack-test (2.1.0)
+      rack (>= 1.3)
+    rails (6.1.7.8)
+      actioncable (= 6.1.7.8)
+      actionmailbox (= 6.1.7.8)
+      actionmailer (= 6.1.7.8)
+      actionpack (= 6.1.7.8)
+      actiontext (= 6.1.7.8)
+      actionview (= 6.1.7.8)
+      activejob (= 6.1.7.8)
+      activemodel (= 6.1.7.8)
+      activerecord (= 6.1.7.8)
+      activestorage (= 6.1.7.8)
+      activesupport (= 6.1.7.8)
+      bundler (>= 1.15.0)
+      railties (= 6.1.7.8)
+      sprockets-rails (>= 2.0.0)
+    rails-dom-testing (2.2.0)
+      activesupport (>= 5.0.0)
+      minitest
+      nokogiri (>= 1.6)
+    rails-html-sanitizer (1.5.0)
+      loofah (~> 2.19, >= 2.19.1)
+    railties (6.1.7.8)
+      actionpack (= 6.1.7.8)
+      activesupport (= 6.1.7.8)
+      method_source
+      rake (>= 12.2)
+      thor (~> 1.0)
+    rake (13.2.1)
+    simple_form (5.3.1)
+      actionpack (>= 5.2)
+      activemodel (>= 5.2)
+    sprockets (4.2.1)
+      concurrent-ruby (~> 1.0)
+      rack (>= 2.2.4, < 4)
+    sprockets-rails (3.5.1)
+      actionpack (>= 6.1)
+      activesupport (>= 6.1)
+      sprockets (>= 3.0.0)
+    sqlite3 (1.6.9)
+      mini_portile2 (~> 2.8.0)
+    thor (1.3.1)
+    timeout (0.4.1)
+    tzinfo (2.0.6)
+      concurrent-ruby (~> 1.0)
+    websocket-driver (0.7.6)
+      websocket-extensions (>= 0.1.0)
+    websocket-extensions (0.1.5)
+    zeitwerk (2.6.16)
+
+PLATFORMS
+  x86_64-linux
+
+DEPENDENCIES
+  rails (~> 6.0)
+  simple_form (~> 5.3.0)
+  simple_form-theme!
+  sqlite3
+
+BUNDLED WITH
+   2.4.22
diff --git a/simple_form-theme.gemspec b/simple_form-theme.gemspec
index af9443c..bbf07c8 100644
--- a/simple_form-theme.gemspec
+++ b/simple_form-theme.gemspec
@@ -20,6 +20,6 @@ Gem::Specification.new do |s|
 
   s.required_ruby_version = '>= 2.6.0', '< 3.1'
 
-  s.add_dependency 'rails', '~> 6.1'
+  s.add_dependency 'rails', '>= 6.0', '< 7.0'
   s.add_dependency 'simple_form', '~> 5.3.0'
 end