diff --git a/rails_6_test_app/Gemfile b/rails_6_test_app/Gemfile
index 18f7466..5b18e18 100644
--- a/rails_6_test_app/Gemfile
+++ b/rails_6_test_app/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 6.0.0'
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3', '~> 1.4'
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 5.3'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
 gem 'jbuilder', '~> 2.7'
 # Use Active Model has_secure_password
diff --git a/rails_6_test_app/Gemfile.lock b/rails_6_test_app/Gemfile.lock
index 2beccbc..ef6968d 100644
--- a/rails_6_test_app/Gemfile.lock
+++ b/rails_6_test_app/Gemfile.lock
@@ -99,7 +99,8 @@ GEM
     nokogiri (1.11.2)
       mini_portile2 (~> 2.5.0)
       racc (~> 1.4)
-    puma (3.12.6)
+    puma (5.3.2)
+      nio4r (~> 2.0)
     racc (1.5.2)
     rack (2.2.3)
     rack-test (1.1.0)
@@ -187,7 +188,7 @@ DEPENDENCIES
   byebug
   jbuilder (~> 2.7)
   listen (>= 3.0.5, < 3.2)
-  puma (~> 3.11)
+  puma (~> 5.3)
   rails (~> 6.0.0)
   rspec-rails (~> 3.8.2)
   spring