diff --git a/Gemfile b/Gemfile
index 43274fa..7bdda99 100644
--- a/Gemfile
+++ b/Gemfile
@@ -19,7 +19,7 @@ gem 'webpacker'
 
 gem 'active_model_serializers'
 # Use Puma as the app server
-gem 'puma', '~> 3.7'
+gem 'puma', '~> 4.3'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets
diff --git a/Gemfile.lock b/Gemfile.lock
index b5c8903..fe5f170 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -104,7 +104,8 @@ GEM
       mini_portile2 (~> 2.4.0)
     pg (0.20.0)
     public_suffix (4.0.1)
-    puma (3.12.1)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-proxy (0.6.5)
       rack
@@ -212,7 +213,7 @@ DEPENDENCIES
   jbuilder (~> 2.5)
   listen (>= 3.0.5, < 3.2)
   pg (= 0.20.0)
-  puma (~> 3.7)
+  puma (~> 4.3)
   rails (~> 5.1.6)
   react-rails
   sass-rails (~> 5.0)