diff --git a/Gemfile b/Gemfile
index 3f184ad..e8e6142 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 5.2.3'
 # Use pg as the database for Active Record
 gem 'pg'
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
 # gem 'jbuilder', '~> 2.5'
 # Build JSON APIs with AMS. Read more https://github.com/rails-api/active_model_serializers/tree/0-10-stable
diff --git a/Gemfile.lock b/Gemfile.lock
index 7c2233f..2eec826 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -84,7 +84,8 @@ GEM
     nokogiri (1.10.3)
       mini_portile2 (~> 2.4.0)
     pg (1.1.4)
-    puma (3.12.1)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-cors (1.0.3)
     rack-test (1.1.0)
@@ -147,7 +148,7 @@ DEPENDENCIES
   byebug
   listen (>= 3.0.5, < 3.2)
   pg
-  puma (~> 3.11)
+  puma (~> 4.3)
   rack-cors
   rails (~> 5.2.3)
   spring