diff --git a/Gemfile b/Gemfile
index 0249290fa..1c4c5d457 100644
--- a/Gemfile
+++ b/Gemfile
@@ -149,9 +149,6 @@ group :development, :test do
   gem 'html2haml',     '2.1.0'
   gem 'sdoc',          '0.4.1'  # bundle exec rake doc:rails generates the API under doc/api.
   gem 'railroady',     '1.3.0'  # to generate database diagrams
-
-  # dev tools
-  gem 'unicorn'
   gem 'autodoc'
 end
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 59ba30d96..c9a17e96c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -284,7 +284,6 @@ GEM
     kaminari (0.16.3)
       actionpack (>= 3.0.0)
       activesupport (>= 3.0.0)
-    kgio (2.11.0)
     launchy (2.4.3)
       addressable (~> 2.3)
     libv8 (3.16.14.19)
@@ -394,7 +393,6 @@ GEM
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
     rainbow (2.2.1)
-    raindrops (0.18.0)
     rake (12.0.0)
     ransack (1.5.1)
       actionpack (>= 3.0)
@@ -525,9 +523,6 @@ GEM
     unf_ext (0.0.7.2)
     unicode-display_width (1.2.0)
     unicode_utils (1.4.0)
-    unicorn (5.3.0)
-      kgio (~> 2.6)
-      raindrops (~> 0.7)
     uniform_notifier (1.9.0)
     uuidtools (2.1.5)
     validates_email_format_of (1.6.3)
@@ -635,7 +630,6 @@ DEPENDENCIES
   therubyracer (= 0.12.2)
   turbolinks (= 2.5.3)
   uglifier (= 2.7.2)
-  unicorn
   uuidtools (= 2.1.5)
   validates_email_format_of (= 1.6.3)
   webmock