diff --git a/Gemfile b/Gemfile
index 5ab99cf..9d58121 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 5.2.3'
 # Use postgresql as the database for Active Record
 gem 'pg', '>= 0.18', '< 2.0'
 # Use Puma as the app server
-gem 'puma', '~> 3.12'
+gem 'puma', '~> 4.3'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
 gem 'active_model_serializers'
 # gem 'jbuilder', '~> 2.5'
diff --git a/Gemfile.lock b/Gemfile.lock
index 15f93ff..8751c71 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -86,7 +86,8 @@ GEM
     nokogiri (1.10.10)
       mini_portile2 (~> 2.4.0)
     pg (1.1.4)
-    puma (3.12.6)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.2.2)
     rack-cors (1.0.5)
       rack (>= 1.6.0)
@@ -149,7 +150,7 @@ DEPENDENCIES
   byebug
   listen (>= 3.0.5, < 3.2)
   pg (>= 0.18, < 2.0)
-  puma (~> 3.12)
+  puma (~> 4.3)
   rack-cors
   rails (~> 5.2.3)
   spring