diff --git a/Gemfile b/Gemfile
index e83b9e1..6cf4440 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 5.2'
 # Use postgresql as the database for Active Record
 gem 'pg', '>= 0.18', '< 2.0'
 # Use Puma as the app server
-gem 'puma', '~> 3.12'
+gem 'puma', '~> 4.3'
 # Need this for service workers to work with Rails
 gem 'serviceworker-rails'
 # Use SCSS for stylesheets
diff --git a/Gemfile.lock b/Gemfile.lock
index d03562b..6e17825 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -125,7 +125,9 @@ GEM
     marcel (0.3.3)
       mimemagic (~> 0.3.2)
     method_source (1.0.0)
-    mimemagic (0.3.5)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
     minitest (5.14.2)
@@ -153,7 +155,8 @@ GEM
     orm_adapter (0.5.0)
     pg (1.1.4)
     public_suffix (4.0.1)
-    puma (3.12.6)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.2.3)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -273,7 +276,7 @@ DEPENDENCIES
   listen (>= 3.0.5, < 3.2)
   omniauth-facebook (= 5.0.0)
   pg (>= 0.18, < 2.0)
-  puma (~> 3.12)
+  puma (~> 4.3)
   rails (~> 5.2)
   rails-controller-testing
   sassc-rails (= 1.3.0)