diff --git a/Gemfile b/Gemfile
index 23bae92..efd3c1b 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,7 +4,7 @@ source 'https://rubygems.org'
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
 gem 'rails', '5.0.0'
 # Use Puma as the app server
-gem 'puma', '3.4.0'
+gem 'puma', '3.12.2'
 # Use SCSS for stylesheets
 gem 'sass-rails', '5.0.6'
 # Use Uglifier as compressor for JavaScript assets
diff --git a/Gemfile.lock b/Gemfile.lock
index e111730..ed06f2e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -118,7 +118,7 @@ GEM
       mime-types
       mimemagic (= 0.3.0)
     pg (0.18.4)
-    puma (3.4.0)
+    puma (3.12.2)
     rack (2.0.6)
     rack-test (0.6.3)
       rack (>= 1.0)
@@ -221,7 +221,7 @@ DEPENDENCIES
   listen (= 3.0.5)
   paperclip (= 4.3.6)
   pg (= 0.18.4)
-  puma (= 3.4.0)
+  puma (= 3.12.2)
   rails (= 5.0.0)
   sass-rails (= 5.0.6)
   spring