diff --git a/Gemfile b/Gemfile
index a6876ca..e529ac1 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,7 +7,7 @@ end
 
 gem 'rails', '5.2.2'
 gem 'pg', '~> 0.18'
-gem 'puma', '~> 3.7'
+gem 'puma', '~> 4.3'
 gem 'sass-rails', '~> 5.0'
 gem 'uglifier', '>= 1.3.0'
 
diff --git a/Gemfile.lock b/Gemfile.lock
index eacecfd..8bb0d57 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -131,7 +131,8 @@ GEM
     pry-rails (0.3.9)
       pry (>= 0.10.4)
     public_suffix (3.0.3)
-    puma (3.12.1)
+    puma (4.3.11)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -229,7 +230,7 @@ DEPENDENCIES
   mini_magick
   pg (~> 0.18)
   pry-rails
-  puma (~> 3.7)
+  puma (~> 4.3)
   rails (= 5.2.2)
   rails-i18n
   sass-rails (~> 5.0)