diff --git a/Gemfile b/Gemfile
index 3883b22..6ec6413 100644
--- a/Gemfile
+++ b/Gemfile
@@ -16,7 +16,7 @@ gem 'friendly_id', '~> 5.2.4'
 gem 'haml-rails', '~> 1.0'
 gem 'jbuilder', '~> 2.5'
 gem 'jquery-rails'
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 gem 'rails', '~> 5.2.2'
 gem 'redcarpet'
 gem 'sass-rails', '~> 5.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index 282beba..c271a50 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -192,7 +192,8 @@ GEM
     pry-rails (0.3.9)
       pry (>= 0.10.4)
     public_suffix (3.0.3)
-    puma (3.12.0)
+    puma (4.3.11)
+      nio4r (~> 2.0)
     rack (2.0.6)
     rack-protection (2.0.5)
       rack
@@ -343,7 +344,7 @@ DEPENDENCIES
   minitest-rails-capybara
   pg
   pry-rails
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 5.2.2)
   rb-readline
   redcarpet