diff --git a/Gemfile b/Gemfile
index 2105e4d..e7aec4c 100644
--- a/Gemfile
+++ b/Gemfile
@@ -13,7 +13,7 @@ gem 'rails', '~> 6.0.2.1'
 # Use postgresql as the database for Active Record
 gem 'pg', '~> 0.18'
 # Use Puma as the app server
-gem 'puma', '~> 3.7'
+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 2458097..e35cf04 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -161,7 +161,9 @@ GEM
     mime-types (3.3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2019.1009)
-    mimemagic (0.3.3)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_magick (4.10.1)
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
@@ -172,7 +174,8 @@ GEM
       mini_portile2 (~> 2.4.0)
     pg (0.21.0)
     public_suffix (4.0.3)
-    puma (3.12.2)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     rack (2.0.8)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -291,7 +294,7 @@ DEPENDENCIES
   listen (>= 3.0.5, < 3.2)
   mailgun-ruby
   pg (~> 0.18)
-  puma (~> 3.7)
+  puma (~> 4.3)
   rails (~> 6.0.2.1)
   rails-controller-testing
   rest-client