diff --git a/Gemfile b/Gemfile
index cfc3775..4a807fe 100644
--- a/Gemfile
+++ b/Gemfile
@@ -23,7 +23,7 @@ group :production do
   gem 'newrelic_rpm'
 end
 
-gem 'puma', '2.14.0'
+gem 'puma', '4.3.12'
 
 # Use Uglifier as compressor for JavaScript assets
 gem 'uglifier', '>= 1.3.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index b6d613f..32275d1 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -101,6 +101,7 @@ GEM
     multi_json (1.11.2)
     multipart-post (1.2.0)
     newrelic_rpm (3.13.0.299)
+    nio4r (2.5.8)
     nokogiri (1.6.1)
       mini_portile (~> 0.5.0)
     oauth (0.4.7)
@@ -130,7 +131,8 @@ GEM
       omniauth (~> 1.0)
     orm_adapter (0.5.0)
     pg (0.17.1)
-    puma (2.14.0)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     quiet_assets (1.0.2)
       railties (>= 3.1, < 5.0)
     rack (1.5.5)
@@ -241,7 +243,7 @@ DEPENDENCIES
   omniauth-bitbucket
   omniauth-github
   pg
-  puma (= 2.14.0)
+  puma (= 4.3.12)
   quiet_assets
   rails (= 4.0.13)
   rspec-collection_matchers