diff --git a/Gemfile b/Gemfile
index 4febefc..8606aaf 100644
--- a/Gemfile
+++ b/Gemfile
@@ -9,7 +9,7 @@ end
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
 gem 'rails', '~> 5.1.1'
 # Use Puma as the app server
-gem 'puma', '~> 3.7'
+gem 'puma', '~> 5.6'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets
diff --git a/Gemfile.lock b/Gemfile.lock
index 0dc8519..adb7f21 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -168,7 +168,9 @@ GEM
     mime-types (3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2016.0521)
-    mimemagic (0.3.2)
+    mimemagic (0.4.3)
+      nokogiri (~> 1)
+      rake
     mini_portile2 (2.2.0)
     minitest (5.10.2)
     mongo (2.4.2)
@@ -195,7 +197,8 @@ GEM
       method_source (~> 0.8.1)
       slop (~> 3.4)
     public_suffix (2.0.5)
-    puma (3.9.1)
+    puma (5.6.2)
+      nio4r (~> 2.0)
     rack (2.0.3)
     rack-contrib (1.2.0)
       rack (>= 0.9.1)
@@ -334,7 +337,7 @@ DEPENDENCIES
   mongoid
   mongoid-enum!
   mongoid_paranoia
-  puma (~> 3.7)
+  puma (~> 5.6)
   rails (~> 5.1.1)
   rails-i18n (~> 5.0.0)
   rspec