diff --git a/Gemfile b/Gemfile
index 8cbf146..b6045d0 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,7 +4,7 @@ git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 ruby '2.5.1'
 gem 'rails', '~> 5.2.2.1'
 gem 'pg', '>= 0.18', '< 2.0'
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 gem 'resque'
 gem 'curb'
 gem 'crono'
diff --git a/Gemfile.lock b/Gemfile.lock
index 6339666..8896e0e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -86,7 +86,9 @@ 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)
@@ -102,7 +104,8 @@ GEM
     pry (0.12.2)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
-    puma (3.12.0)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.6)
     rack-protection (2.0.5)
       rack
@@ -218,7 +221,7 @@ DEPENDENCIES
   listen (>= 3.0.5, < 3.2)
   pg (>= 0.18, < 2.0)
   pry
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 5.2.2.1)
   resque
   sass-rails (~> 5.0)