diff --git a/Gemfile b/Gemfile
index ca9b7428..3dcc176d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,6 +2,8 @@ source "https://rubygems.org"
 
 gem "github-pages", group: :jekyll_plugins
 
+gem "webrick"
+
 group :test do
   gem "html-proofer"
   gem "rake"