diff --git a/Gemfile b/Gemfile
index eda276465..4a3959eba 100644
--- a/Gemfile
+++ b/Gemfile
@@ -13,7 +13,7 @@ gem 'sqlite3', group: :development
 gem 'pg', '0.18.1', group: :production
 gem 'rails_12factor', group: :production
 # 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 fc6888ed8..8e1697463 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -116,7 +116,9 @@ 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_magick (4.10.1)
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
@@ -127,7 +129,8 @@ GEM
       mini_portile2 (~> 2.4.0)
     pg (0.18.1)
     public_suffix (4.0.5)
-    puma (3.12.4)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     rack (2.2.2)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -232,7 +235,7 @@ DEPENDENCIES
   jquery-rails
   listen (>= 3.0.5, < 3.2)
   pg (= 0.18.1)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 5.2.4, >= 5.2.4.1)
   rails_12factor
   rmagick