diff --git a/Gemfile b/Gemfile
index ccc7afd..9152ab0 100644
--- a/Gemfile
+++ b/Gemfile
@@ -12,7 +12,7 @@ gem "rails", "~> 5.1.6"
 # Use postgresql as the database for Active Record
 gem "pg", "~> 1.0.0"
 # 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'
 # Use ActiveModel has_secure_password
diff --git a/Gemfile.lock b/Gemfile.lock
index 0cbcf1a..dc87165 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -131,7 +131,8 @@ GEM
       ast (~> 2.4.0)
     pg (1.0.0)
     powerpack (0.1.1)
-    puma (3.11.4)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     pusher-client (0.6.2)
       json
       websocket (~> 1.0)
@@ -256,7 +257,7 @@ DEPENDENCIES
   minitest-reporters
   octokit (~> 4.0)
   pg (~> 1.0.0)
-  puma (~> 3.7)
+  puma (~> 4.3)
   rack-cors
   rails (~> 5.1.6)
   rails_12factor