diff --git a/Gemfile b/Gemfile
index a11d099..9800a23 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 5.2.3'
 # Use sqlite3 as the database for Active Record
 #gem 'sqlite3'
 # Use Puma as the app server
-gem 'puma', '~> 3.12'
+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 ba220ed..ddbd356 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -110,7 +110,8 @@ GEM
       racc (~> 1.4)
     pg (1.1.4)
     public_suffix (4.0.6)
-    puma (3.12.6)
+    puma (4.3.11)
+      nio4r (~> 2.0)
     racc (1.5.2)
     rack (2.2.3)
     rack-protection (2.1.0)
@@ -217,7 +218,7 @@ DEPENDENCIES
   jbuilder (~> 2.5)
   listen (>= 3.0.5, < 3.2)
   pg (~> 1.1.3)
-  puma (~> 3.12)
+  puma (~> 4.3)
   rails (~> 5.2.3)
   sass-rails (~> 5.0)
   selenium-webdriver