diff --git a/Gemfile b/Gemfile
index 2c52f41..9f8656a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -12,7 +12,7 @@ gem 'rails', '>= 5.2.2.1'
 # 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 292201e..ad0f987 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -140,7 +140,9 @@ GEM
     mime-types (3.2.2)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2018.0812)
-    mimemagic (0.3.3)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mina (1.2.3)
       open4 (~> 1.3.4)
       rake
@@ -168,7 +170,8 @@ GEM
     pry-rails (0.3.6)
       pry (>= 0.10.4)
     public_suffix (3.0.2)
-    puma (3.11.4)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     qiniu (6.9.0)
       mime-types (~> 3.1)
       rest-client (~> 2.0)
@@ -302,7 +305,7 @@ DEPENDENCIES
   pg (>= 0.18, < 2.0)
   pry
   pry-rails
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (>= 5.2.2.1)
   rails-i18n (~> 5.1)
   ransack (= 2.1.1)