diff --git a/Gemfile b/Gemfile
index cdb67be..1ac5765 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,7 +6,7 @@ gem 'rails', '~> 5.0.4'
 # 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/Gemfile.lock b/Gemfile.lock
index d892d3f..b32b020 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -134,6 +134,8 @@ GEM
     nio4r (2.5.8)
     nokogiri (1.13.4-x86_64-darwin)
       racc (~> 1.4)
+    nokogiri (1.13.4-x86_64-linux)
+      racc (~> 1.4)
     notiffany (0.1.3)
       nenv (~> 0.1)
       shellany (~> 0.0)
@@ -143,7 +145,8 @@ GEM
       method_source (~> 1.0)
     pry-rails (0.3.9)
       pry (>= 0.10.4)
-    puma (3.12.6)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     raabro (1.4.0)
     racc (1.6.0)
     rack (2.2.3)
@@ -257,6 +260,7 @@ GEM
 
 PLATFORMS
   x86_64-darwin-20
+  x86_64-linux
 
 DEPENDENCIES
   annotate
@@ -275,7 +279,7 @@ DEPENDENCIES
   listen (~> 3.0.5)
   pg (~> 0.18)
   pry-rails
-  puma (~> 3.0)
+  puma (~> 4.3)
   rack-cors
   rack-livereload
   rails (~> 5.0.4)