diff --git a/Gemfile b/Gemfile
index ef96c09..7d8aad8 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,7 +6,7 @@ ruby '2.6.0'
 # Core
 gem 'rails', '~> 5.2.3'
 gem 'pg', '>= 0.18', '< 2.0'
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 gem 'bootsnap', '>= 1.1.0', require: false
 
 # Frontend
diff --git a/Gemfile.lock b/Gemfile.lock
index 3952646..50dccb1 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -108,7 +108,9 @@ 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 (5.11.3)
@@ -148,7 +150,8 @@ GEM
     pry-rails (0.3.9)
       pry (>= 0.10.4)
     public_suffix (4.0.1)
-    puma (3.12.1)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     pundit (2.1.0)
       activesupport (>= 3.0.0)
     rack (2.0.7)
@@ -270,7 +273,7 @@ DEPENDENCIES
   omniauth-github
   pg (>= 0.18, < 2.0)
   pry-rails
-  puma (~> 3.11)
+  puma (~> 4.3)
   pundit
   rails (~> 5.2.3)
   rubocop-rails