diff --git a/Gemfile b/Gemfile
index 64ec919..9c3b10b 100644
--- a/Gemfile
+++ b/Gemfile
@@ -40,7 +40,7 @@ gem 'rails', '~> 5.2.3'
 # 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 e44abe4..543d6d3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -138,7 +138,9 @@ GEM
     mime-types (3.2.2)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2019.0331)
-    mimemagic (0.3.3)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_magick (4.9.3)
     mini_mime (1.0.1)
     mini_portile2 (2.4.0)
@@ -177,7 +179,8 @@ GEM
     pg (1.1.4)
     pg (1.1.4-x64-mingw32)
     public_suffix (3.1.1)
-    puma (3.12.1)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-proxy (0.6.5)
       rack
@@ -303,7 +306,7 @@ DEPENDENCIES
   omniauth-authsch
   paranoia (~> 2.4, >= 2.4.2)
   pg (>= 0.18, < 2.0)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 5.2.3)
   rails-ujs (~> 0.1.0)
   ransack (~> 2.1, >= 2.1.1)