diff --git a/rails/Gemfile b/rails/Gemfile
index 3456a93..0d89309 100644
--- a/rails/Gemfile
+++ b/rails/Gemfile
@@ -10,7 +10,7 @@ gem 'rails', '~> 6.0.0'
 # Use postgresql as the database for Active Record
 gem 'pg', '>= 0.18', '< 2.0'
 # Use Puma as the app server
-gem 'puma', '~> 3.12'
+gem 'puma', '~> 4.3'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5'
 # Transpile app-like JavaScript. Read more: https://github.com/rails/webpacker
diff --git a/rails/Gemfile.lock b/rails/Gemfile.lock
index 60a2c09..7004c10 100644
--- a/rails/Gemfile.lock
+++ b/rails/Gemfile.lock
@@ -141,7 +141,8 @@ GEM
     pry (0.12.2)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
-    puma (3.12.6)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     rack (2.2.3)
     rack-proxy (0.6.5)
       rack
@@ -280,7 +281,7 @@ DEPENDENCIES
   listen (>= 3.0.5, < 3.2)
   pg (>= 0.18, < 2.0)
   pry
-  puma (~> 3.12)
+  puma (~> 4.3)
   rails (~> 6.0.0)
   rspec-rails
   rubocop (~> 0.59.2)