diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
new file mode 100644
index 0000000..5d1c4ba
--- /dev/null
+++ b/.github/workflows/ci.yaml
@@ -0,0 +1,30 @@
+---
+name: CI
+
+on:
+  workflow_dispatch:
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        ruby-version:
+          - 2.7
+        active-record-version:
+          - 5.2.0
+    env:
+      ACTIVE_RECORD_VERSION: "${{ matrix.active-record-version }}"
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: "${{ matrix.ruby-version }}"
+          bundler-cache: true
+      - name: Run tests
+        run: bundle exec rspec --format documentation
diff --git a/Gemfile b/Gemfile
index 0fe5829..bb44130 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,3 +2,16 @@ source 'https://rubygems.org'
 
 # Specify your gem's dependencies in inheritance_integer_type.gemspec
 gemspec
+
+ar_version = ENV["ACTIVE_RECORD_VERSION"] || "default"
+
+ar = case ar_version
+when "master"
+  { github: "rails/rails" }
+when "default"
+  ">= 5.2"
+else
+  "~> #{ar_version}"
+end
+
+gem "activerecord", ar
diff --git a/Gemfile.lock b/Gemfile.lock
deleted file mode 100644
index 28845fa..0000000
--- a/Gemfile.lock
+++ /dev/null
@@ -1,63 +0,0 @@
-PATH
-  remote: .
-  specs:
-    inheritance_integer_type (0.1.3)
-
-GEM
-  remote: https://rubygems.org/
-  specs:
-    activemodel (5.2.8.1)
-      activesupport (= 5.2.8.1)
-    activerecord (5.2.8.1)
-      activemodel (= 5.2.8.1)
-      activesupport (= 5.2.8.1)
-      arel (>= 9.0)
-    activesupport (5.2.8.1)
-      concurrent-ruby (~> 1.0, >= 1.0.2)
-      i18n (>= 0.7, < 2)
-      minitest (~> 5.1)
-      tzinfo (~> 1.1)
-    arel (9.0.0)
-    coderay (1.1.3)
-    concurrent-ruby (1.2.2)
-    diff-lcs (1.5.0)
-    i18n (1.14.1)
-      concurrent-ruby (~> 1.0)
-    method_source (1.0.0)
-    minitest (5.20.0)
-    pry (0.14.2)
-      coderay (~> 1.1)
-      method_source (~> 1.0)
-    rake (13.1.0)
-    rspec (3.12.0)
-      rspec-core (~> 3.12.0)
-      rspec-expectations (~> 3.12.0)
-      rspec-mocks (~> 3.12.0)
-    rspec-core (3.12.2)
-      rspec-support (~> 3.12.0)
-    rspec-expectations (3.12.3)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.12.0)
-    rspec-mocks (3.12.6)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.12.0)
-    rspec-support (3.12.1)
-    sqlite3 (1.3.13)
-    thread_safe (0.3.6)
-    tzinfo (1.2.11)
-      thread_safe (~> 0.1)
-
-PLATFORMS
-  ruby
-
-DEPENDENCIES
-  activerecord (< 6.0)
-  bundler
-  inheritance_integer_type!
-  pry
-  rake
-  rspec
-  sqlite3 (~> 1.3.6)
-
-BUNDLED WITH
-   2.4.21
diff --git a/inheritance_integer_type.gemspec b/inheritance_integer_type.gemspec
index fe34f32..a58ed2a 100644
--- a/inheritance_integer_type.gemspec
+++ b/inheritance_integer_type.gemspec
@@ -21,7 +21,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "bundler"
   spec.add_development_dependency "rake"
   spec.add_development_dependency "rspec"
-  spec.add_development_dependency "activerecord", "< 6.0"
+  spec.add_development_dependency "activerecord", ">= 5.2"
   spec.add_development_dependency "sqlite3", "~> 1.3.6"
   spec.add_development_dependency "pry"
 end