diff --git a/Gemfile b/Gemfile
index 04dbd53..5e38641 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,7 +2,7 @@ source 'https://rubygems.org'
 
 gem 'rails', '~> 5.0.7', '>= 5.0.7.2'
 gem 'pg', '>= 0.18', '< 2.0'
-gem 'puma', '~> 3.0'
+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 4d94b33..f57fe13 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -132,8 +132,10 @@ GEM
       method_source (~> 1.0)
       spoon (~> 0.0)
     public_suffix (4.0.5)
-    puma (3.12.6)
-    puma (3.12.6-java)
+    puma (4.3.12)
+      nio4r (~> 2.0)
+    puma (4.3.12-java)
+      nio4r (~> 2.0)
     rack (2.2.3)
     rack-test (0.6.3)
       rack (>= 1.0)
@@ -265,7 +267,7 @@ DEPENDENCIES
   listen (~> 3.0.5)
   pg (>= 0.18, < 2.0)
   pry
-  puma (~> 3.0)
+  puma (~> 4.3)
   rails (~> 5.0.7, >= 5.0.7.2)
   rspec-rails (~> 3.0)
   sass-rails (~> 5.0)
@@ -275,7 +277,6 @@ DEPENDENCIES
   turbolinks (~> 5)
   tzinfo-data
   uglifier (>= 1.3.0)
-  warden
   web-console (>= 3.3.0)
 
 BUNDLED WITH