diff --git a/Gemfile b/Gemfile
index 28f2420..01ebedf 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,3 +6,7 @@ source 'http://rubygems.org'
 # Bundler will treat runtime dependencies like base dependencies, and
 # development dependencies will be added by default to the :development group.
 gemspec
+
+group :test do
+  gem 'codecov', require: false
+end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 8eb3e7b..1e8937b 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,5 +1,13 @@
 # frozen_string_literal: true
 
+require 'simplecov'
+SimpleCov.start
+
+if ENV.fetch('CI', '') == 'true'
+  require 'codecov'
+  SimpleCov.formatter = SimpleCov::Formatter::Codecov
+end
+
 require 'shoulda-matchers'
 
 RSpec.configure do |config|