diff --git a/Gemfile b/Gemfile
index d7ffedc..6d6e532 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,3 +2,5 @@
 
 source "https://rubygems.org"
 gemspec
+
+gem "webrick", "~> 1.7"
diff --git a/jekyll-theme-bluelib.gemspec b/jekyll-theme-bluelib.gemspec
index 68969aa..f5f577a 100644
--- a/jekyll-theme-bluelib.gemspec
+++ b/jekyll-theme-bluelib.gemspec
@@ -13,4 +13,5 @@ Gem::Specification.new do |spec|
   spec.files         = `git ls-files -z`.split("\x0").select { |f| f.match(%r!^(assets|_layouts|_includes|_sass|LICENSE|README|_config\.yml)!i) }
 
   spec.add_runtime_dependency "jekyll", "~> 4.2"
+  spec.add_runtime_dependency "webrick", "~> 1.7"
 end