diff --git a/Gemfile b/Gemfile
index 214894e..9bb2c35 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,7 +7,7 @@ ruby '2.4.0'
 
 gem 'rails', '~> 5.2.3'
 gem 'pg', '>= 0.18', '< 2.0'
-gem 'puma', '~> 3.12'
+gem 'puma', '~> 4.3'
 
 # UI
 gem 'bootstrap', '~> 4.3.1'
diff --git a/Gemfile.lock b/Gemfile.lock
index bc27fcf..0140750 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -176,7 +176,9 @@ GEM
     mime-types (3.3)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2019.1009)
-    mimemagic (0.3.3)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
     mini_racer (0.2.6)
@@ -215,7 +217,8 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
     public_suffix (4.0.1)
-    puma (3.12.6)
+    puma (4.3.11)
+      nio4r (~> 2.0)
     rack (2.0.8)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -367,7 +370,7 @@ DEPENDENCIES
   mini_racer
   omniauth-facebook
   pg (>= 0.18, < 2.0)
-  puma (~> 3.12)
+  puma (~> 4.3)
   rails (~> 5.2.3)
   rspec-rails
   sass-rails (~> 5.0)