diff --git a/Gemfile b/Gemfile
index fe95cc9..0450d10 100644
--- a/Gemfile
+++ b/Gemfile
@@ -26,7 +26,7 @@ group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
   gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
   # Use Puma as the app server
-  gem 'puma', '~> 3.11'
+  gem 'puma', '~> 4.3'
 end
 
 group :development do
diff --git a/Gemfile.lock b/Gemfile.lock
index 1ab30fc..8c6e730 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -110,7 +110,9 @@ GEM
     marcel (0.3.3)
       mimemagic (~> 0.3.2)
     method_source (0.9.0)
-    mimemagic (0.3.2)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.1)
     mini_portile2 (2.3.0)
     minitest (5.11.3)
@@ -123,7 +125,8 @@ GEM
       mini_portile2 (~> 2.3.0)
     pg (1.1.3)
     public_suffix (3.0.3)
-    puma (3.12.0)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     pundit (2.0.0)
       activesupport (>= 3.0.0)
     rack (2.0.5)
@@ -200,7 +203,7 @@ DEPENDENCIES
   letter_opener
   listen (>= 3.0.5, < 3.2)
   pg (~> 1.1.3)
-  puma (~> 3.11)
+  puma (~> 4.3)
   pundit (~> 2.0.0)
   rack-cors
   rails (~> 5.2.1)