diff --git a/Gemfile b/Gemfile
index a4a7251..cc81062 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 6.0.0'
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3', '~> 1.4'
 # 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', '~> 2.7'
 # Use Redis adapter to run Action Cable in production
diff --git a/Gemfile.lock b/Gemfile.lock
index ddbea54..331698f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -80,7 +80,9 @@ 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 (5.12.2)
@@ -88,7 +90,8 @@ GEM
     nio4r (2.5.2)
     nokogiri (1.10.4)
       mini_portile2 (~> 2.4.0)
-    puma (3.12.1)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -151,7 +154,7 @@ DEPENDENCIES
   bootsnap (>= 1.4.2)
   byebug
   listen (>= 3.0.5, < 3.2)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 6.0.0)
   spring
   spring-watcher-listen (~> 2.0.0)