diff --git a/Gemfile b/Gemfile
index 85824a8..c39d54a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -13,7 +13,7 @@ gem 'sqlite3'
 gem 'postgresql'
 gem 'elasticsearch'
 # Use Puma as the app server
-gem 'puma', '~> 3.7'
+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 7a825ff..67c8d35 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -106,7 +106,8 @@ GEM
     postgresql (1.0.0)
       pg
     public_suffix (3.0.0)
-    puma (3.10.0)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.3)
     rack-test (0.7.0)
       rack (>= 1.0, < 3)
@@ -198,7 +199,7 @@ DEPENDENCIES
   jbuilder (~> 2.5)
   listen (>= 3.0.5, < 3.2)
   postgresql
-  puma (~> 3.7)
+  puma (~> 4.3)
   rails (~> 5.1.4)
   sass-rails (~> 5.0)
   selenium-webdriver