diff --git a/Gemfile b/Gemfile
index 397d5b9..4f711e8 100644
--- a/Gemfile
+++ b/Gemfile
@@ -9,7 +9,7 @@ gem 'rails', '~> 5.2.4', '>= 5.2.4.3'
 # Use postgresql as the database for Active Record
 gem 'pg', '>= 0.18', '< 2.0'
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets
diff --git a/Gemfile.lock b/Gemfile.lock
index dc0bf57..0bf9654 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -200,7 +200,9 @@ GEM
     mime-types (3.3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2020.0512)
-    mimemagic (0.3.5)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
     minitest (5.14.1)
@@ -237,7 +239,8 @@ GEM
     polyamorous (2.3.2)
       activerecord (>= 5.2.1)
     public_suffix (4.0.5)
-    puma (3.12.6)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     pundit (2.1.0)
       activesupport (>= 3.0.0)
     rack (2.2.3)
@@ -427,7 +430,7 @@ DEPENDENCIES
   listen (>= 3.0.5, < 3.2)
   omniauth-google-oauth2
   pg (>= 0.18, < 2.0)
-  puma (~> 3.11)
+  puma (~> 4.3)
   pundit
   rack
   rails (~> 5.2.4, >= 5.2.4.3)