diff --git a/Gemfile b/Gemfile
index c1d7d55..15703ae 100644
--- a/Gemfile
+++ b/Gemfile
@@ -10,7 +10,7 @@ gem 'fast_jsonapi'
 gem 'jwt'
 gem 'knock'
 gem 'pg', '>= 0.18', '< 2.0'
-gem 'puma', '~> 3.12'
+gem 'puma', '~> 4.3'
 gem 'rails', '~> 5.2.1'
 
 group :development, :test do
diff --git a/Gemfile.lock b/Gemfile.lock
index 6fc2d75..0768f71 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -84,7 +84,9 @@ GEM
     marcel (0.3.2)
       mimemagic (~> 0.3.2)
     method_source (0.9.0)
-    mimemagic (0.3.2)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.0)
     mini_portile2 (2.4.0)
     minitest (5.11.3)
@@ -93,7 +95,8 @@ GEM
     nokogiri (1.10.7)
       mini_portile2 (~> 2.4.0)
     pg (1.0.0)
-    puma (3.12.2)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.1.1)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -180,7 +183,7 @@ DEPENDENCIES
   knock
   listen (>= 3.0.5, < 3.2)
   pg (>= 0.18, < 2.0)
-  puma (~> 3.12)
+  puma (~> 4.3)
   rails (~> 5.2.1)
   rspec-rails
   shoulda-matchers