diff --git a/example/adapter/Gemfile b/example/adapter/Gemfile
new file mode 100644
index 0000000..4d27a5f
--- /dev/null
+++ b/example/adapter/Gemfile
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+source 'https://rubygems.org'
+
+gemspec
+
+group :development do
+  gem 'rubocop', '~> 0.49.0'
+end
+
+group :test, :development do
+  gem 'aruba', '~> 0.8.0'
+  gem 'json', '>= 1.8'
+  gem 'rake', '>= 0.8.7', '< 13.0'
+  gem 'rspec', '~> 3.6.0'
+  gem 'rspec-core', '~> 3.6.0'
+  gem 'rspec-expectations', '~> 3.6.0'
+  gem 'rspec-mocks', '~> 3.6.0'
+  gem 'webmock', '~> 1.18.0'
+end