diff --git a/Gemfile b/Gemfile
index 467c1ab..7a2e8a2 100644
--- a/Gemfile
+++ b/Gemfile
@@ -13,7 +13,7 @@ end
 gem 'rails', '~> 5.1.4'
 
 # Use Puma as the app server
-gem 'puma', '~> 3.7'
+gem 'puma', '~> 4.3'
 
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
 gem 'jbuilder', '~> 2.5'
diff --git a/Gemfile.lock b/Gemfile.lock
index ff1ca1c..0105191 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -211,7 +211,8 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
     public_suffix (3.0.0)
-    puma (3.10.0)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     rack (2.0.3)
     rack-test (0.7.0)
       rack (>= 1.0, < 3)
@@ -370,7 +371,7 @@ DEPENDENCIES
   once-ler
   pg
   pry
-  puma (~> 3.7)
+  puma (~> 4.3)
   rails (~> 5.1.4)
   responders
   rspec-its