diff --git a/RailsCode/toy_app2/Gemfile b/RailsCode/toy_app2/Gemfile
index 8cab89e..bdbacf7 100644
--- a/RailsCode/toy_app2/Gemfile
+++ b/RailsCode/toy_app2/Gemfile
@@ -11,7 +11,7 @@ gem 'rails', '~> 5.0.3'
 # Use postgresql as the database for Active Record
 gem 'pg', '~> 0.18'
 # Use Puma as the app server
-gem 'puma', '~> 3.0'
+gem 'puma', '~> 4.3'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets
diff --git a/RailsCode/toy_app2/Gemfile.lock b/RailsCode/toy_app2/Gemfile.lock
index 27b2a97..fc79120 100644
--- a/RailsCode/toy_app2/Gemfile.lock
+++ b/RailsCode/toy_app2/Gemfile.lock
@@ -41,6 +41,7 @@ GEM
     arel (7.1.4)
     bindex (0.5.0)
     builder (3.2.3)
+    byebug (11.1.3)
     coffee-rails (4.2.2)
       coffee-script (>= 2.2.0)
       railties (>= 4.0.0)
@@ -73,10 +74,14 @@ GEM
     minitest (5.10.2)
     multi_json (1.12.1)
     nio4r (2.1.0)
+    nokogiri (1.7.2)
+      mini_portile2 (~> 2.1.0)
     nokogiri (1.7.2-x64-mingw32)
       mini_portile2 (~> 2.1.0)
+    pg (0.20.0)
     pg (0.20.0-x64-mingw32)
-    puma (3.8.2)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.3)
     rack-test (0.6.3)
       rack (>= 1.0)
@@ -140,6 +145,7 @@ GEM
     websocket-extensions (0.1.2)
 
 PLATFORMS
+  ruby
   x64-mingw32
 
 DEPENDENCIES
@@ -149,7 +155,7 @@ DEPENDENCIES
   jbuilder (~> 2.5)
   jquery-rails
   pg (~> 0.18)
-  puma (~> 3.0)
+  puma (~> 4.3)
   rails (~> 5.0.3)
   sass-rails (~> 5.0)
   turbolinks (~> 5)