diff --git a/Gemfile b/Gemfile
index 5c7f786..a3fdd4f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,7 +1,7 @@
 source 'https://rubygems.org'
 
 gem 'rails', '4.1.7'
-gem 'puma', '2.8.2'
+gem 'puma', '4.3.11'
 gem 'sqlite3', '1.3.9'
 gem 'faraday_middleware', '0.9.0'
 gem 'docker-api', '1.13.0', require: 'docker'
diff --git a/Gemfile.lock b/Gemfile.lock
index 3774c1a..fc7f873 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -68,11 +68,12 @@ GEM
     minitest (5.5.1)
     multi_json (1.10.1)
     multipart-post (1.2.0)
+    nio4r (2.5.8)
     octokit (3.2.0)
       sawyer (~> 0.5.3)
-    puma (2.8.2)
-      rack (>= 1.1, < 2.0)
-    rack (1.5.2)
+    puma (4.3.11)
+      nio4r (~> 2.0)
+    rack (1.5.5)
     rack-test (0.6.3)
       rack (>= 1.0)
     rails (4.1.7)
@@ -155,7 +156,7 @@ DEPENDENCIES
   its
   kmts (= 2.0.1)
   octokit (= 3.2.0)
-  puma (= 2.8.2)
+  puma (= 4.3.11)
   rails (= 4.1.7)
   rspec-rails
   shoulda-matchers (= 2.6.1)