diff --git a/Gemfile b/Gemfile
index 5318f19..83cdeab 100644
--- a/Gemfile
+++ b/Gemfile
@@ -41,7 +41,7 @@ gem 'uglifier', '>= 1.3.0'
 gem 'webpacker', '>= 4.0.x'
 
 gem 'bootsnap'
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 
 gem 'sdoc', '~> 0.4.0', group: :doc
 
diff --git a/Gemfile.lock b/Gemfile.lock
index d3209c5..64e4f8d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -250,7 +250,9 @@ 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)
@@ -286,7 +288,8 @@ GEM
     pry-rails (0.3.9)
       pry (>= 0.10.4)
     public_suffix (3.0.3)
-    puma (3.12.1)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     pundit (2.0.1)
       activesupport (>= 3.0.0)
     rack (2.0.7)
@@ -497,7 +500,7 @@ DEPENDENCIES
   pry-byebug
   pry-coolline
   pry-rails
-  puma (~> 3.11)
+  puma (~> 4.3)
   pundit
   rack-cors
   rails (~> 5.2.0)