diff --git a/Gemfile b/Gemfile
index 9c7111f..1af0540 100644
--- a/Gemfile
+++ b/Gemfile
@@ -12,7 +12,7 @@ gem 'rails', '~> 5.2'
 gem 'mysql2', '>= 0.5.0' #, '< 0.5'
 # Use Puma as the app server
 #gem 'puma', '~> 3.7'
-gem 'puma', '~> 3.12.4'
+gem 'puma', '~> 4.3.12'
 # 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 32fda4a..0429396 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -92,7 +92,9 @@ 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)
@@ -111,7 +113,8 @@ GEM
     nokogiri (1.10.10)
       mini_portile2 (~> 2.4.0)
     public_suffix (4.0.5)
-    puma (3.12.6)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.2.3)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -208,7 +211,7 @@ DEPENDENCIES
   money
   money-rails
   mysql2 (>= 0.5.0)
-  puma (~> 3.12.4)
+  puma (~> 4.3.12)
   rails (~> 5.2)
   rb-readline
   sass-rails (~> 5.0)