diff --git a/Gemfile b/Gemfile
index 7388928..2378ab4 100644
--- a/Gemfile
+++ b/Gemfile
@@ -5,7 +5,7 @@ source 'https://rubygems.org'
 gem 'rails', '~> 5.0.0', '>= 5.0.0.1'
 
 # Use Puma as the app server
-gem 'puma', '~> 3.0'
+gem 'puma', '~> 3.12'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets
diff --git a/Gemfile.lock b/Gemfile.lock
index d7b7279..145aa86 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -81,7 +81,7 @@ GEM
     nokogiri (1.6.8.1)
       mini_portile2 (~> 2.1.0)
     pg (0.19.0)
-    puma (3.6.1)
+    puma (3.12.6)
     rack (2.0.1)
     rack-test (0.6.3)
       rack (>= 1.0)
@@ -161,7 +161,7 @@ DEPENDENCIES
   jquery-rails
   listen (~> 3.0.5)
   pg
-  puma (~> 3.0)
+  puma (~> 3.12)
   rails (~> 5.0.0, >= 5.0.0.1)
   sass-rails (~> 5.0)
   spring