diff --git a/Gemfile b/Gemfile
index cebebed..3e55bc4 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 5.2.4', '>= 5.2.4.1'
 # Use sqlite3 as the database for Active Record
 gem 'pg'
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
 # gem 'jbuilder', '~> 2.5'
 # Use Redis adapter to run Action Cable in production
diff --git a/Gemfile.lock b/Gemfile.lock
index f3c237c..6564050 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -130,7 +130,8 @@ GEM
     os (1.0.1)
     pg (1.2.2)
     public_suffix (4.0.3)
-    puma (3.12.2)
+    puma (4.3.11)
+      nio4r (~> 2.0)
     rack (2.2.1)
     rack-cors (1.1.1)
       rack (>= 2.0.0)
@@ -226,7 +227,7 @@ DEPENDENCIES
   google-cloud-storage (~> 1.8)
   listen (>= 3.0.5, < 3.2)
   pg
-  puma (~> 3.11)
+  puma (~> 4.3)
   rack-cors
   rails (~> 5.2.4, >= 5.2.4.1)
   rspec-rails (~> 3.9)