diff --git a/Gemfile b/Gemfile
index 053c27d..37f5eaa 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,2 +1,2 @@
 source 'https://rubygems.org'
-gem 'github-pages'
+gem 'github-pages', group: :jekyll_plugins
diff --git a/_config.yml b/_config.yml
index a1608e6..0862eaf 100644
--- a/_config.yml
+++ b/_config.yml
@@ -18,3 +18,4 @@ kramdown:
 
 gems:
     - jekyll-redirect-from
+    - jekyll-sitemap