diff --git a/colorls.gemspec b/colorls.gemspec
index bb876ced..c5090233 100644
--- a/colorls.gemspec
+++ b/colorls.gemspec
@@ -57,5 +57,6 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'rubocop'
   spec.add_development_dependency 'rubocop-rspec'
   spec.add_development_dependency 'rubygems-tasks'
+  spec.add_development_dependency 'simplecov'
 end
 # rubocop:enable Metrics/BlockLength
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 8dc27cd5..8b15977d 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,3 +1,6 @@
+require 'simplecov'
+SimpleCov.start
+
 require 'bundler/setup'
 require 'colorls'