diff --git a/Gemfile b/Gemfile
index c369a8c..db1a354 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,7 +11,7 @@ gem 'pg', '>= 0.18', '< 2.0'
 
 gem "select2-rails"
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5'
 # Transpile app-like JavaScript. Read more: https://github.com/rails/webpacker
diff --git a/Gemfile.lock b/Gemfile.lock
index d787459..3ccf5dc 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -112,7 +112,8 @@ 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-proxy (0.6.5)
       rack
@@ -214,7 +215,7 @@ DEPENDENCIES
   jbuilder (~> 2.7)
   listen (>= 3.0.5, < 3.2)
   pg (>= 0.18, < 2.0)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 6.0.0)
   sass-rails (~> 5)
   select2-rails