diff --git a/Gemfile b/Gemfile
index c399c69..df7f7f9 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,7 +11,7 @@ gem 'fog',                     '1.36.0'
 gem 'will_paginate',           '3.1.6'
 gem 'bootstrap-will_paginate', '0.0.10'
 gem 'bootstrap-sass',          '3.4.1'
-gem 'puma',                    '~> 3.12'
+gem 'puma',                    '~> 4.3'
 gem "font-awesome-rails",      '4.7.0.5'
 gem 'sass-rails',              '5.0.7'
 gem 'uglifier',                '2.5.3'
diff --git a/Gemfile.lock b/Gemfile.lock
index 9f14316..acb2a8d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -277,7 +277,8 @@ GEM
     pry (0.12.2)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
-    puma (3.12.1)
+    puma (4.3.9)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -403,7 +404,7 @@ DEPENDENCIES
   pg (~> 0.18)
   prawn (= 2.2.2)
   prawn-table (= 0.2.2)
-  puma (~> 3.12)
+  puma (~> 4.3)
   rails (= 5.2.3)
   rails-controller-testing
   rails_12factor (= 0.0.2)