diff --git a/Gemfile b/Gemfile
index f689b4d..18a1e2d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 5.2.4'
 # 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'
 # 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 4c16bcf..93c0052 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -93,7 +93,9 @@ GEM
     marcel (0.3.3)
       mimemagic (~> 0.3.2)
     method_source (0.9.2)
-    mimemagic (0.3.3)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
     minitest (5.13.0)
@@ -105,7 +107,8 @@ GEM
     parser (2.6.5.0)
       ast (~> 2.4.0)
     pg (1.1.4)
-    puma (3.12.1)
+    puma (4.3.9)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -213,7 +216,7 @@ DEPENDENCIES
   faker (~> 1.8, >= 1.8.4)
   listen (>= 3.0.5, < 3.2)
   pg (>= 0.18, < 2.0)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 5.2.4)
   rspec-rails (~> 3.6, >= 3.6.1)
   rspec_junit_formatter