diff --git a/Gemfile b/Gemfile
index cdcb3d8..634edab 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,6 +8,7 @@ group :development, :test do
   gem "rake"
   gem "pry"
   gem "rspec-rails", "~> 2.0"
+  gem "puma"
 end
 
 group :test do
diff --git a/Gemfile.lock b/Gemfile.lock
index 196487b..5f43149 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -11,7 +11,6 @@ PATH
       i18n_generators (= 1.2.1)
       jbuilder (~> 2.0)
       jquery-rails (~> 3.1.0)
-      puma
       rails (= 4.1.1)
       sass-rails (~> 4.0.3)
       sqlite3
@@ -229,6 +228,7 @@ DEPENDENCIES
   factory_girl_rails
   fluentd-ui!
   pry
+  puma
   rake
   rspec-rails (~> 2.0)
   simplecov (~> 0.7.1)
diff --git a/fluentd-ui.gemspec b/fluentd-ui.gemspec
index fc001c1..6321cda 100644
--- a/fluentd-ui.gemspec
+++ b/fluentd-ui.gemspec
@@ -20,7 +20,6 @@ Gem::Specification.new do |spec|
 
   spec.add_dependency "fluentd", "0.10.46"
   spec.add_dependency 'rails', '4.1.1'
-  spec.add_dependency 'puma'
   spec.add_dependency 'sucker_punch', "~> 1.0.5"
   spec.add_dependency 'i18n_generators', '1.2.1'
   spec.add_dependency 'bcrypt', '~> 3.1.5'