diff --git a/Gemfile b/Gemfile
index 290b971..dd53e34 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', '~> 3.11'
+gem 'puma', '~> 4.3'
 # Authtentication of users
 # gem 'devise_token_auth'
 # ActiveModel::Serializer implementation and Rails hooks
diff --git a/Gemfile.lock b/Gemfile.lock
index b2b4993..eea7fa3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -105,7 +105,8 @@ GEM
       mini_portile2 (~> 2.4.0)
     pg (1.1.4)
     public_suffix (4.0.1)
-    puma (3.12.1)
+    puma (4.3.11)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-cors (1.0.3)
     rack-test (1.1.0)
@@ -179,7 +180,7 @@ DEPENDENCIES
   jwt
   listen (>= 3.0.5, < 3.2)
   pg (>= 0.18, < 2.0)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rack-cors
   rails (~> 5.2.3)
   rails-i18n (~> 5.1)