diff --git a/Gemfile b/Gemfile
index d99e181..0d20086 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,7 +11,7 @@ end
 gem 'rails', '~> 5.2.3'
 
 # Use Puma as the app server
-gem 'puma', '~> 3.12'
+gem 'puma', '~> 4.3'
 
 # Use SCSS for stylesheets
 gem 'sassc-rails'
diff --git a/Gemfile.lock b/Gemfile.lock
index 7dc7d6a..2685774 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -214,7 +214,8 @@ GEM
     pg (0.21.0)
     popper_js (1.14.5)
     public_suffix (3.1.1)
-    puma (3.12.4)
+    puma (4.3.9)
+      nio4r (~> 2.0)
     racc (1.5.2)
     rack (2.2.3)
     rack-test (1.1.0)
@@ -381,7 +382,7 @@ DEPENDENCIES
   omniauth-twitter
   pagy
   pg (~> 0.18)
-  puma (~> 3.12)
+  puma (~> 4.3)
   rails (~> 5.2.3)
   rails-controller-testing
   random_password