diff --git a/Gemfile b/Gemfile
index 1cada11..6038ccd 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 5.2.3'
 # Use mysql as the database for Active Record
 gem 'mysql2', '>= 0.4.4', '< 0.6.0'
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
 # gem 'jbuilder', '~> 2.5'
 # Use Redis adapter to run Action Cable in production
diff --git a/Gemfile.lock b/Gemfile.lock
index 75a9f9c..ed0e260 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -74,7 +74,9 @@ GEM
     mime-types (3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2016.0521)
-    mimemagic (0.3.3)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.1)
     mini_portile2 (2.4.0)
     minitest (5.11.3)
@@ -85,7 +87,8 @@ GEM
     nokogiri (1.10.3)
       mini_portile2 (~> 2.4.0)
     park_info (0.8.0)
-    puma (3.12.1)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -154,7 +157,7 @@ DEPENDENCIES
   listen (>= 3.0.5, < 3.2)
   mysql2 (>= 0.4.4, < 0.6.0)
   park_info
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 5.2.3)
   rest-client
   spring