diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index f5b431383..ee75d9fb6 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -40,7 +40,18 @@ jobs:
         with:
           ruby-version: "${{ matrix.ruby }}"
           bundler-cache: true
-      - run: bundle exec rake ${{ matrix.task }}
+      - run: NO_COVERAGE=true bundle exec rake ${{ matrix.task }}
+
+  coverage:
+    runs-on: ubuntu-latest
+    name: "Test coverage"
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: "3.2"
+          bundler-cache: true
+      - run: bundle exec rake spec
 
   edge-rubocop:
     runs-on: ubuntu-latest
diff --git a/.gitignore b/.gitignore
index 93bd86757..f7286ff5b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,3 +17,6 @@ pkg
 
 .ruby-gemset
 .ruby-version
+
+# simplecov generated
+coverage
diff --git a/.simplecov b/.simplecov
new file mode 100644
index 000000000..56bda648b
--- /dev/null
+++ b/.simplecov
@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+SimpleCov.start do
+  enable_coverage :branch
+  minimum_coverage line: 99.86, branch: 95.33
+  add_filter '/spec/'
+  add_filter '/vendor/bundle/'
+end
diff --git a/Gemfile b/Gemfile
index fa7613df2..f6fddf529 100644
--- a/Gemfile
+++ b/Gemfile
@@ -10,6 +10,7 @@ gem 'rake'
 gem 'rspec', '~> 3.11'
 gem 'rubocop-performance', '~> 1.7'
 gem 'rubocop-rake', '~> 0.6'
+gem 'simplecov', '>= 0.19'
 gem 'yard'
 
 local_gemfile = 'Gemfile.local'
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index cf19e9f84..006ad539b 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -3,6 +3,8 @@
 require 'rubocop'
 require 'rubocop/rspec/support'
 
+require 'simplecov' unless ENV['NO_COVERAGE']
+
 module SpecHelper
   ROOT = Pathname.new(__dir__).parent.freeze
 end