diff --git a/.gitignore b/.gitignore
index 8624f93..1bb1e05 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,4 @@ bin
 *.gemfile.lock
 .ruby-version
 .ruby-gemset
+.byebug_history
diff --git a/rack-attack.gemspec b/rack-attack.gemspec
index f446cd6..07f2931 100644
--- a/rack-attack.gemspec
+++ b/rack-attack.gemspec
@@ -41,4 +41,9 @@ Gem::Specification.new do |s|
   #
   # See https://github.com/guard/guard-minitest/pull/131
   s.add_development_dependency 'guard'
+
+  # byebug only works with MRI
+  if RUBY_ENGINE == "ruby"
+    s.add_development_dependency 'byebug'
+  end
 end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 0378797..7cfc1b5 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -15,6 +15,10 @@ rescue LoadError
   #nothing to do here
 end
 
+if RUBY_ENGINE == "ruby"
+  require "byebug"
+end
+
 class MiniTest::Spec
 
   include Rack::Test::Methods