diff --git a/Gemfile b/Gemfile
index ec4b64c..1b5aa0c 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ ruby '2.5.3'
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
 gem 'rails', '~> 5.2.1'
 # Use Puma as the app server
-gem 'puma', '~> 3.12'
+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 a17ae9d..435a911 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -243,7 +243,8 @@ GEM
       pry (>= 0.10.4)
     psych (3.0.3)
     public_suffix (4.0.6)
-    puma (3.12.6)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     racc (1.5.2)
     rack (2.2.3)
     rack-cors (1.0.5)
@@ -409,7 +410,7 @@ DEPENDENCIES
   pg (>= 0.20.0)
   pry-byebug
   pry-rails
-  puma (~> 3.12)
+  puma (~> 4.3)
   rack-cors (>= 1.0.2)
   rails (~> 5.2.1)
   rails-controller-testing