diff --git a/Gemfile b/Gemfile
index c27b625..afcefad 100644
--- a/Gemfile
+++ b/Gemfile
@@ -12,7 +12,7 @@ gem 'dotenv-rails'
 gem 'pg'
 gem 'devise'
 gem 'activeadmin'
-gem 'puma', '~> 3.7'
+gem 'puma', '~> 4.3'
 gem 'sass-rails', '~> 5.0'
 gem 'uglifier', '>= 1.3.0'
 gem 'jbuilder', '~> 2.5'
diff --git a/Gemfile.lock b/Gemfile.lock
index 99b0f82..896b587 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -244,7 +244,8 @@ GEM
     pry-rails (0.3.6)
       pry (>= 0.10.4)
     public_suffix (3.0.1)
-    puma (3.11.0)
+    puma (4.3.11)
+      nio4r (~> 2.0)
     rack (2.2.2)
     rack-proxy (0.6.2)
       rack
@@ -397,7 +398,7 @@ DEPENDENCIES
   poltergeist
   progress_bar
   pry-rails
-  puma (~> 3.7)
+  puma (~> 4.3)
   rails (~> 5.1.4)
   recursive-open-struct
   redcarpet