diff --git a/Gemfile b/Gemfile
index 38afe19..fc7b92a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -12,7 +12,7 @@ gem 'devise'
 gem 'execjs'
 gem 'paperclip', '~> 6.1.0'
 gem 'pg', '~> 1.1'
-gem 'puma', '~> 3.12'
+gem 'puma', '~> 4.3'
 gem 'rails', '~> 5.1.7'
 gem 'react-rails'
 gem 'sass-rails', '~> 5.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index cedbe2c..f8cf66c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -137,7 +137,8 @@ GEM
       binding_of_caller (>= 0.7)
       pry (>= 0.9.11)
     public_suffix (3.0.3)
-    puma (3.12.6)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.2.3)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -268,7 +269,7 @@ DEPENDENCIES
   pry-byebug (~> 3.4.0)
   pry-rails (~> 0.3.4)
   pry-stack_explorer (~> 0.4.9)
-  puma (~> 3.12)
+  puma (~> 4.3)
   rails (~> 5.1.7)
   rails-controller-testing (~> 1.0)
   react-rails