diff --git a/Gemfile b/Gemfile
index f6be2e52..15ac4e49 100644
--- a/Gemfile
+++ b/Gemfile
@@ -21,9 +21,7 @@ end
 # "lock_manager" is specified in development dependencies, to allow
 # the use of unreleased versions of "lock_manager" during development.
 group(:development, :test) do
-  gem 'debug', '>= 1.0.0'
   gem 'fakefs'
-  gem 'json'
   gem 'lock_manager', *location_for(ENV['LOCK_MANAGER_LOCATION'] || '>= 0')
   gem 'packaging', *location_for(ENV['PACKAGING_LOCATION'] || '~> 0.99')
   gem 'pry-byebug', require: false