diff --git a/website/Gemfile b/website/Gemfile
index 39d3081..cb075d6 100644
--- a/website/Gemfile
+++ b/website/Gemfile
@@ -11,7 +11,7 @@ gem 'rails', '~> 5.1.4'
 # Use mysql as the database for Active Record
 gem 'mysql2', '>= 0.3.18', '< 0.5'
 # Use Puma as the app server
-gem 'puma', '~> 3.7'
+gem 'puma', '~> 4.3'
 # Use SCSS for stylesheets
  gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets
diff --git a/website/Gemfile.lock b/website/Gemfile.lock
index c96b5ce..024872c 100644
--- a/website/Gemfile.lock
+++ b/website/Gemfile.lock
@@ -74,7 +74,8 @@ GEM
     nio4r (2.2.0)
     nokogiri (1.10.5)
       mini_portile2 (~> 2.4.0)
-    puma (3.11.2)
+    puma (4.3.9)
+      nio4r (~> 2.0)
     rack (2.0.8)
     rack-test (0.8.2)
       rack (>= 1.0, < 3)
@@ -152,7 +153,7 @@ DEPENDENCIES
   coffee-rails (~> 4.2)
   listen (>= 3.0.5, < 3.2)
   mysql2 (>= 0.3.18, < 0.5)
-  puma (~> 3.7)
+  puma (~> 4.3)
   rails (~> 5.1.4)
   sass-rails (~> 5.0)
   spring-watcher-listen (~> 2.0.0)