diff --git a/Gemfile b/Gemfile
index edf0a3d..15cb39b 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 5.2.3'
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3'
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 gem 'rails_admin', '~> 2.0.0.beta'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
 # gem 'jbuilder', '~> 2.5'
diff --git a/Gemfile.lock b/Gemfile.lock
index cfab4c4..78da41d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -100,7 +100,9 @@ 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 (1.0.1)
     mini_portile2 (2.4.0)
     minitest (5.11.3)
@@ -109,7 +111,8 @@ GEM
     nio4r (2.3.1)
     nokogiri (1.10.3)
       mini_portile2 (~> 2.4.0)
-    puma (3.12.1)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     rack (2.0.7)
     rack-pjax (1.1.0)
       nokogiri (~> 1.5)
@@ -199,7 +202,7 @@ DEPENDENCIES
   bootsnap (>= 1.1.0)
   byebug
   listen (>= 3.0.5, < 3.2)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 5.2.3)
   rails_admin (~> 2.0.0.beta)
   spring