diff --git a/Gemfile b/Gemfile
index e98db80..53117e0 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ ruby '2.5.1'
 gem 'mysql2', '>=0.4.10'
 gem 'rails', '~> 5.2.0'
 # Use Puma as the app server
-gem 'puma', '~> 3.0'
+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 ee9db55..3dee5c4 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -135,7 +135,9 @@ 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_mime (1.0.1)
     mini_portile2 (2.4.0)
     minitest (5.11.3)
@@ -174,7 +176,8 @@ GEM
     pastel (0.7.2)
       equatable (~> 0.5.0)
       tty-color (~> 0.4.0)
-    puma (3.12.1)
+    puma (4.3.11)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-cors (1.0.3)
     rack-test (1.1.0)
@@ -298,7 +301,7 @@ DEPENDENCIES
   omniauth-google-oauth2
   omniauth-nctu!
   overcommit
-  puma (~> 3.0)
+  puma (~> 4.3)
   rack-cors
   rails (~> 5.2.0)
   ransack (>= 2.0.0)