diff --git a/udemy-learn-ruby-on-rails-from-scratch/myrubyblog/Gemfile b/udemy-learn-ruby-on-rails-from-scratch/myrubyblog/Gemfile
index 5f6c437..48fc59e 100644
--- a/udemy-learn-ruby-on-rails-from-scratch/myrubyblog/Gemfile
+++ b/udemy-learn-ruby-on-rails-from-scratch/myrubyblog/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 5.2.3'
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3'
 # Use Puma as the app server
-gem 'puma', '~> 5.5'
+gem 'puma', '~> 4.3'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets
diff --git a/udemy-learn-ruby-on-rails-from-scratch/myrubyblog/Gemfile.lock b/udemy-learn-ruby-on-rails-from-scratch/myrubyblog/Gemfile.lock
index 795d4a9..f3fa013 100644
--- a/udemy-learn-ruby-on-rails-from-scratch/myrubyblog/Gemfile.lock
+++ b/udemy-learn-ruby-on-rails-from-scratch/myrubyblog/Gemfile.lock
@@ -161,7 +161,7 @@ GEM
       racc (~> 1.4)
     orm_adapter (0.5.0)
     public_suffix (4.0.6)
-    puma (4.3.8)
+    puma (4.3.9)
       nio4r (~> 2.0)
     racc (1.5.2)
     rack (2.2.3)
@@ -281,7 +281,7 @@ DEPENDENCIES
   devise
   jbuilder (~> 2.5)
   listen (>= 3.0.5, < 3.2)
-  puma (~> 5.5)
+  puma (~> 4.3)
   rails (~> 5.2.3)
   sass-rails (~> 5.0)
   selenium-webdriver