diff --git a/Gemfile b/Gemfile
index 6015c303d1..0cfa9f88c0 100644
--- a/Gemfile
+++ b/Gemfile
@@ -10,3 +10,4 @@ gem 'test-unit-ruby-core'
 gem 'rubocop', '>= 1.31.0'
 gem 'gettext'
 gem 'prism', '>= 0.30.0'
+gem 'webrick'