diff --git a/section_1/MyApp/Gemfile b/section_1/MyApp/Gemfile
index a0d6591..bbd69e5 100644
--- a/section_1/MyApp/Gemfile
+++ b/section_1/MyApp/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', '~> 3.11'
+gem 'puma', '~> 4.3'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets
diff --git a/section_1/MyApp/Gemfile.lock b/section_1/MyApp/Gemfile.lock
index 89716dd..54e0b62 100644
--- a/section_1/MyApp/Gemfile.lock
+++ b/section_1/MyApp/Gemfile.lock
@@ -146,7 +146,9 @@ GEM
     marcel (0.3.3)
       mimemagic (~> 0.3.2)
     method_source (0.9.2)
-    mimemagic (0.3.3)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
     mini_racer (0.2.4)
@@ -190,7 +192,8 @@ GEM
       equatable (~> 0.6)
       tty-color (~> 0.5)
     public_suffix (4.0.1)
-    puma (3.12.1)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-proxy (0.6.5)
       rack
@@ -323,7 +326,7 @@ DEPENDENCIES
   foreman
   jbuilder (~> 2.5)
   listen (>= 3.0.5, < 3.2)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 5.2.3)
   rails-hyperstack (~> 1.0.alpha1.0)
   sass-rails (~> 5.0)