diff --git a/Gemfile b/Gemfile
index ff1d5ce6..047b1c99 100644
--- a/Gemfile
+++ b/Gemfile
@@ -5,7 +5,7 @@ source 'https://rubygems.org'
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
 gem 'rails', '~> 5.2.2'
 # Use Puma as the app server
-gem 'puma', '~> 3.12'
+gem 'puma', '~> 4.3'
 # Use Redis adapter to run Action Cable in production
 # gem 'redis', '~> 3.0'
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 8070e4b7..b3535464 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -279,7 +279,8 @@ GEM
       binding_of_caller (>= 0.7)
       pry (>= 0.9.11)
     public_suffix (3.0.2)
-    puma (3.12.0)
+    puma (4.3.5)
+      nio4r (~> 2.0)
     pundit (1.1.0)
       activesupport (>= 3.0.0)
     rack (2.0.6)
@@ -446,7 +447,7 @@ DEPENDENCIES
   pry-rails (~> 0.3.9)
   pry-rescue (~> 1.4.4)
   pry-stack_explorer (~> 0.4.9.2)
-  puma (~> 3.12)
+  puma (~> 4.3)
   pundit (~> 1.1.0)
   rack-cors
   rails (~> 5.2.2)