diff --git a/Gemfile b/Gemfile
index 719125f..f8e765e 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', '4.3.12'
 gem 'faraday_middleware', '0.9.0'
 gem 'sqlite3', '1.3.9'
 gem 'active_model_serializers', '0.9.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index 0c91a25..7b26154 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -55,9 +55,10 @@ GEM
     multi_json (1.10.1)
     multipart-post (1.2.0)
     netrc (0.7.7)
-    puma (2.8.2)
-      rack (>= 1.1, < 2.0)
-    rack (1.5.2)
+    nio4r (2.5.8)
+    puma (4.3.12)
+      nio4r (~> 2.0)
+    rack (1.5.5)
     rack-test (0.6.2)
       rack (>= 1.0)
     rails (4.1.7)
@@ -125,7 +126,7 @@ DEPENDENCIES
   coveralls (= 0.7.0)
   database_cleaner (= 1.3.0)
   faraday_middleware (= 0.9.0)
-  puma (= 2.8.2)
+  puma (= 4.3.12)
   rails (= 4.1.7)
   rspec-rails (= 2.14.2)
   shoulda-matchers (= 2.6.1)