diff --git a/Gemfile b/Gemfile
index 3a72062..9ba535a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -9,7 +9,7 @@ versions = JSON.parse(Net::HTTP.get(URI('https://pages.github.com/versions.json'
 gem 'github-pages', versions['github-pages']
 
 # https://github.com/jekyll/jekyll/issues/8523
-gem "webrick", "~> 1.7"
+gem 'webrick', '~> 1.7'
 
 group :development do
   gem 'colored'