diff --git a/Gemfile b/Gemfile
index 80532dd..25d819f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -17,7 +17,7 @@ end
 
 gem 'bcrypt', '~> 3.1.7'
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+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 e0979c6..72f8e84 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -117,7 +117,8 @@ GEM
     pg (1.2.3)
     popper_js (1.16.0)
     public_suffix (4.0.3)
-    puma (3.12.2)
+    puma (4.3.9)
+      nio4r (~> 2.0)
     rack (2.1.1)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -229,7 +230,7 @@ DEPENDENCIES
   jquery-rails
   listen (>= 3.0.5, < 3.2)
   pg
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 5.2.4, >= 5.2.4.1)
   rails-controller-testing
   sass-rails (~> 5.0)