diff --git a/.gitignore b/.gitignore
index 6ac3bde4..ff60d0fb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,3 +8,4 @@
 /doc/api
 /Gemfile.lock
 /coverage
+.yardoc
diff --git a/Gemfile b/Gemfile
index 98a52cc3..a2bc4dd1 100644
--- a/Gemfile
+++ b/Gemfile
@@ -14,6 +14,7 @@ gem 'rake'
 gem 'rack', git: 'https://github.com/rack/rack.git'
 gem 'rack-test', '>= 0.6.2'
 gem "minitest", "~> 5.0"
+gem 'yard'
 
 gem "rack-protection", path: "rack-protection"
 gem "sinatra-contrib", path: "sinatra-contrib"