diff --git a/Gemfile b/Gemfile
index dcf4ad0..dfc34ac 100644
--- a/Gemfile
+++ b/Gemfile
@@ -13,7 +13,7 @@ gem "actionview", ">= 5.1.6.2"
 # Use postgresql as the database for Active Record
 gem "pg", "~> 0.18"
 # Use Puma as the app server
-gem "puma", "~> 3.12"
+gem "puma", "~> 4.3"
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
 # gem 'jbuilder', '~> 2.5'
 # Use Redis adapter to run Action Cable in production
diff --git a/Gemfile.lock b/Gemfile.lock
index 298e524..be73cb6 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -95,7 +95,8 @@ GEM
       pry (~> 0.10)
     pry-rails (0.3.9)
       pry (>= 0.10.4)
-    puma (3.12.2)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.2.2)
     rack-cors (1.1.1)
       rack (>= 2.0.0)
@@ -176,7 +177,7 @@ DEPENDENCIES
   pg (~> 0.18)
   pry-byebug
   pry-rails
-  puma (~> 3.12)
+  puma (~> 4.3)
   rack-cors
   rails (~> 5.1.4)
   rubocop