diff --git a/Gemfile b/Gemfile
index 0842c2b..4196b59 100644
--- a/Gemfile
+++ b/Gemfile
@@ -9,7 +9,7 @@ end
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
 gem 'rails', '~> 5.1.4'
 # Use Puma as the app server
-gem 'puma', '~> 3.7'
+gem 'puma', '~> 4.3'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
 gem 'jbuilder', '~> 2.7'
 # Use Redis adapter to run Action Cable in production
diff --git a/Gemfile.lock b/Gemfile.lock
index 3789545..bbc5b8e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -136,7 +136,8 @@ GEM
       rack (>= 1.2, < 3)
     pg (0.21.0)
     public_suffix (3.1.0)
-    puma (3.12.1)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-pjax (1.1.0)
       nokogiri (~> 1.5)
@@ -248,7 +249,7 @@ DEPENDENCIES
   listen (>= 3.0.5, < 3.2)
   oauth2 (~> 1.4)
   pg (~> 0.21.0)
-  puma (~> 3.7)
+  puma (~> 4.3)
   rails (~> 5.1.4)
   rails_admin (~> 1.2)
   redis-rails