diff --git a/Gemfile b/Gemfile
index ef9ca36..2c08aa9 100644
--- a/Gemfile
+++ b/Gemfile
@@ -5,7 +5,7 @@ ruby '2.5.3'
 
 gem 'rails', '~> 5.2.2'
 gem 'sqlite3', '~> 1.3.6'
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 gem 'sass-rails', '~> 5.0'
 gem 'uglifier', '>= 1.3.0'
 gem 'coffee-rails', '~> 4.2'
diff --git a/Gemfile.lock b/Gemfile.lock
index d8f3369..c6aff67 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -104,7 +104,8 @@ GEM
       mini_portile2 (~> 2.5.0)
       racc (~> 1.4)
     public_suffix (4.0.6)
-    puma (3.12.6)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     racc (1.5.2)
     rack (2.2.3)
     rack-test (1.1.0)
@@ -199,7 +200,7 @@ DEPENDENCIES
   coffee-rails (~> 4.2)
   jbuilder (~> 2.5)
   listen (>= 3.0.5, < 3.2)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 5.2.2)
   sass-rails (~> 5.0)
   selenium-webdriver