diff --git a/Gemfile b/Gemfile
index 992c8b3..8309bf9 100644
--- a/Gemfile
+++ b/Gemfile
@@ -15,7 +15,7 @@ gem 'rails', '~> 5.2.3'
 
 gem 'will_paginate', '3.1.6'
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 # 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 24d3cac..6b6f4d9 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -274,7 +274,9 @@ GEM
     mime-types (3.3)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2019.0904)
-    mimemagic (0.3.3)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_magick (4.9.4)
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
@@ -299,7 +301,8 @@ GEM
     pg (1.1.4)
     pg (1.1.4-x64-mingw32)
     public_suffix (3.1.1)
-    puma (3.12.1)
+    puma (4.3.11)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -428,7 +431,7 @@ DEPENDENCIES
   mini_magick (= 4.9.4)
   minitest-reporters
   pg
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 5.2.3)
   rails-controller-testing
   sass-rails (~> 5.0)