diff --git a/Gemfile b/Gemfile
index 6aeadeb..9018add 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,7 +6,7 @@ end
 
 ruby '2.3.3'
 gem 'rails', '~> 5.1.1'
-gem 'puma', '~> 3.7'
+gem 'puma', '~> 4.3'
 gem 'sass-rails', '~> 5.0'
 gem 'uglifier', '>= 1.3.0'
 gem 'turbolinks', '~> 5'
diff --git a/Gemfile.lock b/Gemfile.lock
index d2b7d86..37e1313 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -196,7 +196,8 @@ GEM
     pry-rails (0.3.5)
       pry (>= 0.9.10)
     public_suffix (3.0.2)
-    puma (3.11.2)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     pundit (1.1.0)
       activesupport (>= 3.0.0)
     rack (2.0.4)
@@ -349,7 +350,7 @@ DEPENDENCIES
   omniauth-linkedin-oauth2
   pg
   pry-rails
-  puma (~> 3.7)
+  puma (~> 4.3)
   pundit
   rails (~> 5.1.1)
   rails_admin